Introduction
“Physics One Liners” is the comprehensive collection of important points which represent an unprecedented level of topic wise details of Physics and will be helpful in the preparation of SSC - Staff Selection Commission, Banking, Junior Engineer, RBI, RRB, Railways, Insurance, UPSC, and all other Competitive exams.
One Liners
SSC CGL Physics - Points:
- A diode is used for purifications.
- A most common function of a diode is to allow an electric current to pass in one direction while blocking current in the opposite direction.
- Microwave is used for communication by artificial satellites.
- Microwave was discovered in 1864 by James clerk Maxwell.
- Sound travels in a straight line, sound travels like waves, a sound is a form of energy.
- When a ray of light enters the slab of glass from the air, its wavelength decreases.
- The larger iceberg melts down from the lower surface instead of the upper surface due to more pressure in lower surface the melting point of ice decrease.
- Fixed dimension is found in frequency modulation.
- When the speed of the car is doubled then the breaking force of the car to stop it at the same distance will be four times.
- The dimension of the momentum is the same as that of impulse.
- Time is a fundamental quantity.
- Mass, Time, Temperature, Electric current, Luminous Intensity, Length and Amount of substance are the fundamental quantities.
- When a ring of metal is heated then its hole expands.
- If the diameter of a capillary is doubled, then the rise of water in it will be half.
- Due to surface tension the needle of iron swims on the water surface when it is kept gently.
- Raindrops fall from a great height they fall with that ultimate velocity which is different for different droplets.
- One kilowatt hour is equal to 3.6 Mega Joule.
- 11 km/sec is the minimum escape velocity of a rocket to be launched into space.
- The sun remains behind us and we face raindrops when we see the rainbow.
- The splitting of different colours of light in a prism is dispersion of light.
SSC CGL Physics - Points:
- Surface tension in a liquid is due to cohesiveforce between molecules.
- When a circular plate, a cube and a sphere, all made up of the same material and having the same mass, are heated to 300°C and left in the room, then the sphere among them will have the slowest rate of cooling.
- A person standing on a railway platform listens to the whistles of arriving and departing trains.
- The whistle heard is of the higher pitch when the train arrives.
- An ice block with a piece of lead embedded in it floats in water if the ice melts the water level remains the same.
- The velocity of heat radiation in the vacuum is equal to that of light.
- The substance which conducts current in the solid state is graphite.
- High temperature and low pressure represents the easiest way to liquify a gas.
- Colour of light is related to amplitude.
- Bernoulli’s law explains the working of the hydraulic brakes in automobiles.
- Mercury vapour and argon is the most commonly used substance in a fluorescent lamp.
- When a bottle of scent is open in a corner of a room its odour is felt in all parts of the room. This phenomenon is known as diffusion.
- Speed of sound is greatest in the glass.
- Graphite is a good conductor of electricity.
- In case of Wind Mill grinding wheat grain kinetic energy will be used in performing work.
- Infra Red is a part of sun light which makes the solar cooker hot.
- If the velocity-time graph of a particle is represented by y=mx+c, then the particle is moving with constant acceleration.
- A passenger standing in the bus is thrown outward when the bus takes a sudden turn, this happens due to Inertia of motion.
- When pressure is Increased the melting point of ice decreases.
- Longitudinal waves cannot travel through Vacuum.
SSC CGL Physics - Points:
- The wavelength of visible spectrum is 1300A-3000A.
- Radar was invented by A.H. Taylor & Leo C. Young.
- Radio Detection and Ranging (Radar).
- Romer measured the velocity of light first.
- When a vehicle passes, TV reception gets distorted. This is because sparks plug creates electromagnetic disturbances.
- Tungsten is used for the manufacturing of the filament of an electric bulb because It has a very high melting point.
- The sky appears blue because of Scattering of Light.
- Blue light is scattered in all directions by the tiny molecules of air in Earth’s atmosphere. Blue is scattered more than other colours because it travels as shorter, smaller waves. This is why the sky appears blue most of the time.
- Dynamo is a device for converting Mechanical energy into electrical energy.
- The working of the quartz crystal in the watch is based on Piezoelectric effect.
- Piezoelectric Effect is the ability of certain materials to generate an electric charge in response to applied mechanical stress.
- A big fire in the open appear to be fanned by strong winds because the surrounding heated air rises and cool air rushes in to create a fanning effect.
- Oil rises up the wick in a lamp because of the capillary action phenomenon.
- Capillary action is the phenomenon by which any liquid rises up in a wick or tube. It is due to surface tension of liquids. The height of rice up of liquid depends upon surface tension of the water. This occurs in small plants also.
- In the atmosphere, ultraviolet rays are absorbed by Ozone.
- Pyrex glass variety of glass is heat resistant.
- Cryogenic engines are used in rockets.
- A cryogenic rocket engine is a rocket engine that uses a cryogenic fuel or oxidizer, that is, its fuel or oxidizer (or both) are gases liquefied and stored at very low temperatures.
- The fourth state of matter is known as plasma.
- Plasma can be created by heating a gas or subjecting it to a strong electromagnetic field, applied with a laser or microwave generator at temperatures above 5000 °C.
SSC CGL Physics - Points:
- Lambert's law is related to Illumination.
- Lambert’s law stated that absorbance of a material sample is directly proportional to its thickness.
- Law of conservation of mass validates the statement that matter can neither be created nor destroyed.
- Decibel is the unit used for intensity of sound.
- Bleeding occurs through nose in high mountainous region because the pressure of blood in capillaries is greater than the outside pressure.
- To an astronaut in a spacecraft, the sky appears to be dark.
- Danger signals are generally red as red light because it undergoes the least deviation.
- A simple microscope consists of a short focus convex lens.
- An oil drop spreads over water because the surface tension of oil is much smaller than that of water.
- The device which converts AC to DC is Rectifier.
- When the main switch of the house is put off it disconnects the live wire only.
- Boyle’s law is a relationship between pressure and volume.
- Thorium is radioactive.
- Heat resistant variety of glass is Flint glass.
- The light from the Sun reaches the Earth in about 8 seconds.
- Steam produces more severe burns.
- Short sight in human eyes can be corrected by proper use of concave lens.
- Atmospheric refraction is the reason for twinkling the stars.
- Impure camphor is purified by sublimation.
- A multimeter is used to measure current, voltage and resistance.
SSC CGL Physics - Points:
- Diamonds are glittering and attractive because light incident on them undergoes multiple internal reflections.
- Prism is used to split the white light into different colours.
- Submersed objects can be located using SONAR.
- Sound Navigation and Ranging (SONAR) is a technique that uses sound propagation to navigate, communicate with or detect objects on or under the surface of the water, such as other vessels.
- Spectrometer is used to study dispersion of light.
- A fountain pen works on the principle of capillary action.
- Pycnometer is an instrument used to measure density.
- Fibre-Optics works on the principle of Total Internal reflections.
- A decibel is a measure of sound level.
- A device used for converting A.C. into D.C. is called rectifier.
- An antibiotic is a chemical synthesised by a micro-organism against another micro-organism.
- Energy of ultra violet rays is greater than cosmic rays.
- To an astronaut sky appears dark.
- The sky appears blue from earth because the light from the sun gets scattered by the dust particles and water vapour present in the earth’s atmosphere and among all the light rays of different wavelengths present in polychromatic sunlight, the blue light scatters the most. In outer space atmosphere is absent and hence such scattering doesn’t occur. Thus the outer space appears dark to an astronaut in space.
- Newton defined the law of Gravitation.
- ‘IC’ in computers stands for integrated circuit.
- A hydrogen balloon floats up because of weight of the balloon is less than the weight of the air displaced by it.
- In a rechargeable cell, chemical energy is stored with in the cell.
- An astronaut in outer space will observe sky as black.
- Cylindrical lens should be used to correct the defect of astigmatism.
SSC CGL Physics - Points:
- The first thermionic valve was invented by J.A. Fleming.
- Invented in 1904 by John Ambrose Fleming.
- Superconductors are those elements whose resistance falls almost zero at very low temperatures.
- The energy stored in a watch spring is potential energy.
- The sensation of weightlessness in a spacecraft in an orbit is due to the acceleration in the orbit which is equal to the acceleration due to gravity outside.
- ‘Therm’ is the unit of heat.
- The cream gets separated out of the milk when it is churned. This is due to the centrifugal force.
- Newton’s first law of motion gives the concept of inertia.
- Newton’s first law of motion - An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.
- The process by which the sun’s rays reach the earth is radiation.
- Radiation from the Sun, which is more popularly known as sunlight, is a mixture of electromagnetic waves ranging from infrared (IR) to ultraviolet rays (UV).
- A pond of water appears less deep due to refraction.
- Refraction is the bending of a wave when it enters a medium where its speed is different.
- The oldest type of energy known to man is solar power.
- Energy that is produced commercially from coal is called Thermal Energy.
- Water pipes in hilly areas often burst on a cold frosty night, because the water in the pipes freezes water expands, so pipes break.
- A parachute descends slowly whereas a stone dropped from the same height falls rapidly because a parachute has a larger surrounding area and air resistance.
- Sling Psychomotor is used to measure humidity.
- The period of revolution of a geostationary satellite 24 hours.
- Mirror used in the headlamp of cars is parabolic concave.
SSC CGL Physics - Points:
- Flat footed camels can walk easily in sandy deserts because the pressure on the sand is decreased by increasing the area of the surface in contact.
- Refraction is the reason for a swimming pool to appear less deep than the actual depth is.
- Alternating current is converted into direct current by a rectifier.
- Pasteurisation is the process in which milk is heated to 63°C for 30 minutes.
- Steel is most elastic among a rubber, wet clay, plastic and steel.
- The freezer in a refrigerator is fitted near the top It facilitates convection currents.
- The swing of a spinning cricket ball in the air can be explained on the basis of Buoyancy of air.
- Two thin shirts can keeps us warmer than a single thick shirt because air layer between two shirts behaves like a insulating media.
- The ionosphere of the earth’s atmosphere reflects the radio waves to the earth.
- Water is not effective in extinguishing a fire caused by petrol because water and petrol are immiscible with each other and petrol which forms the upper layer continue to burn.
- Helium gas is used in gas balloons instead of hydrogen gas because it is lighter than hydrogen.
- In a photocell light energy is converted into electrical energy.
- IC chips for computers are usually made of Silicon.
- Nano technology deals with objects with dimensions in the range of 10–9 m.
- The blue wavelength of light is most effective in photosynthesis.
- A falling drop of rainwater acquires the spherical shape due to Surface Tension.
- The weakest of all fundamental forces is Gravitational force.
- The velocity of sound in the air does not change with the change of Pressure of air.
- The density of a gas is maximum at Low temperature, high pressure.
- According to the theory of relativity, Velocity of light always remains constant.
SSC CGL Physics - Points:
- The spoon dropped by an astronaut in a satellite will continue to follow the motion of the satellite.
- Pipelines in cold countries often burst in winter, because water freezes and expands in its volume.
- When a body is taken from earth to moon, weight changes but the mass remains the same.
- A mirage occurs because of total internal reflection by layers of air.
- Due to low air pressure it is difficult to breathe at higher altitudes.
- Name of S. Chandrashekhar is associated with Astrophysics.
- Bolometer is used to measure Temperature.
- A soap bubble shows colours when illuminated with white light. This is due to Interference.
- The instrument used to see the distant objects on the Earth is Terrestrial telescope.
- A person is hurt on kicking a stone due to Reaction.
- The fuse in our domestic electric circuit melts when there is a high rise in Current.
- The diving board is an example of a cantilever beam.
- It is difficult to cook rice at the top of a mountain.
- A dynamo is a device which converts mechanical energy into electrical energy.
- X-rays were discovered by Roentgen.
- Clay is highly plastic.
- The device used to change the speed of an electric fan is Regulator.
- Adiabatic demagnetization principle is used to produce ‘low-temperatures’.
- A photo-electric cell converts Light energy to electrical energy.
- Two stones of different masses are dropped simultaneously from the top of a building Both the stones reach the ground at the same time.
SSC CGL Physics - Points:
- A concave lens always forms an image which is virtual and erect.
- The modulus of rigidity is the ratio of Volume stress to volume strain.
- The propagation of sound waves in a gas involves adiabatic compression and rarefaction.
- If the input frequency of a full wave rectifier is n, the output frequency would be 2n.
- Noise is measured in Decibel.
- The bats can fly in the dark because they generate ultrasonic sound waves.
- No change will happen when a bowl of ice and water kept at exactly zero degree Celsius.
- The acceleration due to gravity at the equator is less than that at the poles.
- Angle of friction and angle of repose are equal to each other.
- If a boy sitting in a train, which is moving at a constant velocity, throws a ball straight up into the air, the ball will fall into his hand.
- The intensity of the gravitational field of the earth is maximum at the pole.
- The spokes used in the wheel of the bicycle increase its Moment of Inertia.
- A transformer works on the principle of Mutual Induction.
- The sky appears blue because the atmosphere scatters blue colour more than the others.
- A clear cloudless day-time sky is blue because molecules in the air scatter bluelight from the sun more than they scatter red light.
- The device in communication satellites which receives signals from an earth station and transmits them to different direction is transponder.
- When a ship enters the sea from a river it rises a little.
- Two stones of unequal masses are thrown vertically up with the same velocity, both will reach the same height.
- The scientist who first sent electromagnetic waves to distant places is James Clerk Maxwell.
- The centre of gravity of a sprinter during the race lies ahead of his feat.
SSC CGL Physics - Points:
- Electron microscope was discovered by Knoll and Ruska.
- A metal plate with a circular hole at the centre is heated. What will happen to the area of the hole Increase.
- A piece of paper and a cricket ball are dropped from the same height, both reach the surface simultaneously if they dropped in vacuum.
- A rocket works on the principle of conservation of Linear momentum.
- The frequency of ultrasound wave is typically Above 20,000 kHz.
- Optical fibres are based on the phenomenon of Total Internal Reflection.
- Now a days yellow lamps are frequently used as street lights. Sodium gases is used in these lamps.
- ‘Mirage’ is an example of refraction and total internal reflection of light.
- The phenomenon of light associated with the appearance of blue colour of the sky is Scattering.
- The function of ball bearings in a wheel is to convert kinetic friction into rolling friction.
- ‘Shock-absorbers’ are usually made of steel as it has higher elasticity.
- The time period of a pendulum when taken to the Moon would increase.
- Sound travels fastest in Steel.
- The rear side of the moon was photographed by Luna 3.
- Luna 3 or E-2A No.1 was a Soviet spacecraft launched in 1959 as part of the Luna Programme. It was the first-ever mission to photograph the far side of the Moon.
- The first electronic digital computer contain valves.
- Lambert’s law is related to Illumination.
- Sir Frank Whittle invented the Jet Engine.
- One can distinguish a telescope from a microscope by observing length and size of the lens.
- The sound produced by a bat is ultrasonic.
SSC CGL Physics - Points:
- When a bar magnet is cut into two equal halves, the pole strength of each piece remains the same.
- Electrostatic precipitator is used to control Air pollution.
- X-Rays were discovered by Roentgen.
- The time period of a seconds pendulum is 2 second.
- The aperture determines the sharpness of image in a camera.
- For a person having hypermetropia, the near point is infinite. In MRI machine Magnetic waves is used.
- A spherical ball made of steel when dropped in mercury container will be on the surface of mercury. The ball will float on mercury because of different densities.
- The sounds having a frequency of 20 Hertz to 20,000 Hertz are known as Audible sounds.
- Eclipses occur due to optical phenomena, is known as a rectilinear propagation.
- Gamma rays have greatest similarity with Xrays.
- In the past, the distinction between X-rays and gamma rays was based on energy (or equivalently frequency or wavelength), with gamma rays being considered a higher energy version of X-rays.
- In the absence of ozone layer, Ultraviolet rays will enter into atmosphere.
- When a vibrating tuning fork is placed on a table, a loud sound is heard. This is due to forced vibrations.
- A piece of wood is held under water. The up thrust on it will be less than weight of the wood.
- Light houses are places with powerful lights to guide and warn the ships coming from different directions in the ocean.
- To eliminate the glare of headlights in motor cars polaroids are used.
- The substances which have infinite electrical resistance are called insulators.
- A liquid is said to boil when its vapour pressure equals the surrounding pressure.
- With an ascent of every 165 meters, the temperature is reduced by 1°C.
- Pressure cooker is fast in cooking rice because high pressure raises the boiling point of water.
SSC CGL Physics - Points:
- It takes more time to cook potatoes on mountain tops because the atmospheric pressure is low.
- Water and ice crystals are in equilibrium at 0°C. When pressure is applied to this system more of ice becomes water.
- ‘Lumen’ is the unit of Luminous flux.
- Luminous flux is the quantity of the energy of the light emitted per second in all directions.
- The mass of 10 moles of water is 180 g.
- Frictional force is a ‘dissipative force’.
- If a magnet has a third pole, then the third pole is called consequent pole.
- If a resistive wire is elongated, its resistance increases.
- Mercury is generally used in thermometers because it has a high conductivity.
- Most metals are good conductors of heat and they are solids at room temperature. Mercury is the only one in liquid state at room temperature. It’s used in thermometers because it has high coefficient of expansion. Hence, the slightest change in temperature is notable when it’s used in a thermometer.
- To an observer on the lunar surface, during daytime, the sky will appear to be Black.
- Mass is the measure of ‘inertia’.
- The intensity of a wave follows inverse square law and is proportional to the square of the amplitude.
- A person opens his mouth on hearing a thunder in order to equalise pressure of air on both sides of the ear drum.
- When ice is heated from 0° C to 10° C, the volume of water first increases then decreases.
- Two bodies of the same mass are thrown with equal speed from the top of a tower simultaneously. One body (x) is thrown vertically downwards. The other (y) is thrown horizontally, both reaches ground with same Kinetic energy.
- An apparatus used for locating submerged objects is known as sonar.
- Sonar (originally an acronym for Sound Navigation And Ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, commu-nicate with or detect objects on or under the surface of the water, such as other vessels.
- Convex mirror is used in a view finding mirror of a vehicle.
- Convex mirrors are curved mirrors that give a “compressed” view rather than a flat view. As a result, they cover a wider field of view and objects in the mirror appear smaller.
SSC CGL Physics - Points:
- We receive sunlight on earth surface, these beams of light are of random type.
- Earth is a very big magnet. Its magnetic field extends north to south.
- The ultimate source of energy in a hydroelectric power station is the potential energy of water.
- A form of condensation that reduces visibility and causes breathing problems is Smog.
- Smog is a type of air pollutant. This kind of visible air pollution is composed of nitrogen oxides, sulphur oxides, ozone, smoke or particulates among others (less visible pollutants include carbon monoxide, CFCs and radioactive sources). Human-made smog is derived from coal emissions, vehicular emissions, industrial emissions, forest and agricultural fires and photochemical reactions of these emissions.
- Instruments can be shielded from outside magnetic effects by surrounding them with Iron shield.
- Centrifugal force is a pseudo force.
- In Newtonian mechanics, the centrifugal force is an inertial force (also called a ‘fictitious’ or ‘pseudo’ force) directed away from the axis of rotation that appears to act on all objects when viewed in a rotating reference frame.
- The hydraulic brake used in automobiles is a direct application of Pascal’s law.
- Processes which are helpful in the prevention of rusting of iron are applying grease, galvanising and painting.
- Supersonic air planes create a shock wave called Sonic boom.
- When an aircraft passes through the air it creates a series of pressure waves in front of it and behind it, similar to the bow and stern waves created by a boat. These waves travel at the speed of sound, and as the speed of the object increases, the waves are forced together, or compressed, because they cannot get out of the way of each other. Eventually they merge into a single shock wave.
- The danger signals are red while the eye is more sensitive to yellow because absorption in red is less than yellow and hence red is visible from a distance.
- On the moon, an astronaut cannot drink lemonade with the help of a straw because there is no atmosphere on the moon.
- A particle moving with uniform speed may have uniform velocity.
- Device which uses sound waves for detection and ranging is called Radar.
- Radar is an object-detection system that uses radio waves to determine the range, angle, or velocity of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain.
- Pound, Kilogram and Gram are units of weight.
- The materials which are weakly repelled by magnets are called dia-magnetic materials.
- Diamagnetic materials are repelled by a magnetic field, an applied magnetic field creates an induced magnetic field in them in the opposite direction, causing a repulsive force. In contrast, paramagnetic and ferromagnetic materials are attracted by a magnetic field.
SSC CGL Physics - Points:
- 25 cm is the distance of ‘distinct vision’ for normal eye.
- A body which is a good absorber of heat is also a good radiator.
- Semiconductor materials are Silicon and Germanium.
- A semiconductor is a substance, usually a solid chemical element or compound that can conduct electricity under some conditions but not others, making it a good medium for the control of electrical current.
- The materials which are strongly attracted by magnet are called ferro magnetic substances.
- Ferromagnetism is the basic mechanism by which certain materials (such as iron) form permanent magnets, or are attracted to magnets.
- In a pin hole camera, we usually get inverted impression.
- The kinetic energy of gas molecules Increases with rise of temperature.
- The average kinetic energy of a gas particle is directly proportional to the temperature. An increase in temperature increases the speed in which the gas molecules move. All gases at a given temperature have the same average kinetic energy. Lighter gas molecules move faster than heavier molecules.
- The first dynamo based on Faraday’s principles was built in 1832 by Hippolyte Pixii.
- It is easier for a man to swim in sea water, than in river water because the density of sea water is more than the density of river water.
- In the remote control of television, electromagnetic waves used are infrared.
- A vehicle will topple if its centre of gravity is outside its base.
- A transistor is an amplifying device.
- The density of water is maximum at 4°C.
- Clothes made of polyester dry quickly after washing because polyester absorbs very little water.
- When a gas is compressed both pressure and temperature increase.
- Metric system of measurement started in the country in 1956.
- electromagnetic nature of light was discovered by Maxwell.
- Time of exposure required for taking photograph of an object depends upon the brightness of the object.
SSC CGL Physics - Points:
- The ordinary and maximum tolerance limit of sound by human being is 60 db to 80 db (decibel).
- Persistence of vision is responsible for the working of Newton’s colour disc experiment.
- A combination of red, green and blue in the circular disc will yield the same result. This is due to the phenomenon called persistence of vision.
- The dimension MLT-2 corresponds to force.
- Plank is the founder of quantum theory of radiation.
- Fibre optics cable used in communication, works on the principle of total internal reflection of light.
- Total internal reflection is the phenomenon which occurs when a propagated wave strikes a medium boundary at an angle larger than a particular critical angle with respect to the normal to the surface.
- In plant water relationships, symbol 'Øw' is used to represent Water potential.
- Photon is the fundamental unit/quantum of light.
- A liquid disturbed by stirring comes to rest due to viscosity.
- The viscosity of a fluid is a measure of its resistance to gradual deformation by shear stress or tensile stress.
- When Arsenic atoms are added to Germanium lattice, it becomes a Extrinsic semiconductor.
- The ambient air is stable when the ambient lapse rate is Sub adiabatic.
- The filter over which sewage is sprinkled is called as Trickling filter.
- It consists of a fixed bed of rocks, lava, coke, gravel, slag, polyurethane foam, sphag-num peat moss, ceramic, or plastic media over which sewage or other wastewater flows down-ward and causes a layer of microbial slime (bio film) to grow, covering the bed of media.
- In the resistance colour code, the fourth band signifies tolerance level.
- The fourth colour band indicates the resistor’s tolerance. Tolerance is the percentage of error in the resistor’s resistance, or how much more or less you can expect a resistor’s actual measured resistance to be from its stated resistance. A gold tolerance band is 5% tolerance, silver is 10%, and no band at all would mean a 20% tolerance.
- In Astrophysics, White hole is a hypothetical hole in outer space from which stars and energy emerge.
- In general relativity, a white hole is a hypothetical region of space time which cannot be entered from the outside, although matter and light can escape from it. In this sense, it is the reverse of a black hole, which can only be entered from the outside and from which matter and light cannot escape.
- Light scattering takes place in Colloidal solutions.
SSC CGL Physics - Points:
- A good conductor while carrying current is positively charged.
- Phytochrome plant pigments absorbs in red and far-red region of light.
- Phytochrome is a photoreceptor, a pigment that plants and some bacteria and fungi, use to detect light. It is sensitive to light in the red and farred region of the visible spectrum.
- The process through which excess of light energy is dissipated in photosynthesis is known as Quenching.
- Ultraviolet rays can be used in water treatment as Disinfectant.
- The device used for measuring the wavelength of X-rays is Bragg Spectrometer.
- Scanning Electron Microscope produces images, which are three dimensional.
- When sound travels from air to water the quantity that remains unchanged is frequency.
- A leaf appears green in daylight. When seen in red light it appears to be black.
- In sunlight or white light the green leaf absorbs all constituents light colours of white except green. It means the leaf absorbs all wavelengths of colours i.e. violet, indigo, blue, yellow, orange, red but not green. Since the green light alone is reflected thus leaf appears green. Under the red light all colours including the green are absorbed in the red colour. Hence the leaf appears as dark.
- Polarisation shows that light is a transverse wave.
- Rex-Bionics – a New Zealand based firm has developed robotic legs to walk, stand, turn and climb.
- A normal medium sized washing machine used in household use electricity 500 Watts.
- Sextant is used to measure height of an object.
- A sextant is a doubly reflecting navigation instrument that measures the angle between two visible objects. The primary use of a sextant is to measure the angle between an astronomical object and the horizon for the purposes of celestial navigation.
- Photoelectric effect supports particle nature of photons.
- Electromagnetic radiation in order of their increasing wavelength X – Ray, infrared, visible, microwave.
- Spontaneous change is one in there is a lowering of free energy.
- Instrument used to study the behaviour of a vibrating string is Sonometer.
- Binary system would be recognised by digital circuits.
SSC CGL Physics - Points:
- ‘Farad’ is the unit of Capacitance.
- It is named after Michael Faraday. The farad measures how much electric charge is accumulated on the capacitor. 1 farad is the capacitance of a capacitor that has charge of 1 coulomb when applied voltage drop of 1 volt.
- Microwaves is odd among Optical fibre, twisted pair wire, Microwaves and Coaxial cable,.
- Communication satellites are used to receive and redirect communication signal.
- Steel is more elastic than rubber because it is deformed very easily.
- Solids which conduct electricity at higher temperature but not at lower temperature are called semi-conductor.
- A television channel is characterised by frequency of transmitted signal.
- The density of water is 1 g/cc. This is strictly valid at 4°C.
- The process of photosynthesis involves conversion of solar energy into chemical energy.
- In radio-communication, the signals emitted by transmitting antenna are reflected on ionosphere.
- The threshold frequency is the frequency below which photo electric emission is not possible.
- Threshold frequency is defined as the minimum frequency of incident light which can cause photo electric emission i.e. this frequency is just able to eject electrons without giving them additional energy.
- Sir C. V. Raman was awarded Nobel Prize for his work on Light Scattering.
- C. V. Raman won the 1930’s Nobel Prize in Physics “for his work on the scattering of light and for the discovery of the Raman Effect”. He was the first Asian and first non-white to receive any Nobel Prize in the sciences.
- Tesla is a unit of magnetic field.
- The damage of the human body due to radiation X-rays or g-rays etc, is measured in Reins.
- Flywheel is an important part of a steam engine’ because it helps the engine in keeping the speed uniform.
- Transition ions absorb light in visible region.
- The unit of noise pollution (level) is decibel.
- Relative humidity is expressed as Percentage.
SSC CGL Physics - Points:
- Relative humidity is the ratio of the partial pressure of water vapour to the equilibrium vapour pressure of water at a given temperature. Relative humidity depends on temperature and the pressure of the system of interest.
- The first stable product of photosynthesis is Phosphoglyceric acid.
- According to special theory of relativity the mass of a particle increases with increase in velocity with respect to an observer.
- The motion of the wheels of a bullock-cart while moving on the road is an example of Translatory and rotatory motion.
- Super conductors are substances that offer minimum resistance to flow of electric current.
- A thin oil film on a water surface appears coloured because of interference.
- A tachometer is a device used to measure speed of rotation.
- The moment of inertia of a body does not depend upon its angular velocity.
- To open a door easily. the handle should be fixed at the greatest distance from the hinges.
- Light from the Sun reaches us in nearly 8 min.
- Radar is used to detect and locate distant objects.
- Radar is an object-detection system that uses radio waves to determine the range, angle, or velocity of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain.
- Optical fibre works on the principle of total internal reflection.
- A particle is moving in a uniform circular motion with constant speed v along a circle of radius r. The acceleration of the particle is [latex]\frac{V}{r^{2}}[/latex].
- Thermopile can be used to detect radiant heat.
- In the Formation of rainbow the phenomenon of total internal reflection of light is used.
- Period of oscillation of 3 cm microwaves in seconds is 1 x [latex]{10}^{-10}[/latex].
- The sky appears blue due to Rayleigh scattering.
- Rayleigh scattering refers to the scattering of light off of the molecules of the air, and can be extended to scattering from particles up to about a tenth of the wavelength of the light.
- The device used to convert solar energy into electricity is Photovoltaic cell.
SSC CGL Physics - Points:
Herman Hollerith had perfected his tabulating system and developed a machine called Tabulation Engine.
The machine was developed to help process data for the 1890 U.S. Census. It spawned a class of machines, known as unit record equipment, and the data processing industry.
The velocity of light is 3 × [latex]{10}^{8}[/latex] m/sec.
A seconds pendulum is a pendulum whose time period is 2 seconds.
A seconds pendulum is a pendulum whose period is precisely two seconds, one second for a swing in one direction and one second for the return swing, a frequency of [latex]\frac{1}{2}[/latex] Hz. A pendulum is a weight suspended from a pivot so that it can swing freely.
A jug is filled the brim with water at 0°C. A piece of ice floats in it. The moment the ice melts water level is unchanged.
Absorption of water from cut ends of stems disproves the cohesion-tension theory.
The cohesion-tension theory is a theory of intermolecular attraction that explains the process of water flow upwards (against the force of gravity) through the xylem of plants. It was proposed in 1894 by John Joly and Henry Horatio Dixon.
Electric current is measured using Ammeter.
It is easy to burst a gas-filled balloon with a needle than with a nail. It is because needle exerts more pressure than nail on the balloon.
The velocity of sound in moist air is more than in dry air because the moist air has less density than dry air.
X-rays can be used to detect defects in precious stones and diamonds.
Ice is packed in saw dust because saw dust is poor conductor of heat.
For a missile launched with a velocity less than the earth’s escape velocity, the total energy is Negative.
A Fuse wire is characterised by low resistance and low melting point.
The purpose of choke in a fluorescent lamp is to decrease the current flow.
The mercury and sodium street lamps light up because of atomic emission.
A person can jump higher on the moon’s surface than on the earth because the acceleration due to gravity in moon is smaller than that on the earth.
The apparent weight of a man in a lift is less the real weight when the lift is going down with an acceleration.
When we exert a force on the floor of the lift i.e. our weight, according to Newton’s third law the floor of the lift exerts an equal and opposite force on us. This reaction force is felt as the apparent weight and is called normal reaction force.
SSC CGL Physics - Points:
- Rainbows are produced when sunlight Incident on rain drops hanging in the atmosphere is dispersed after suffering refraction and internal reflection.
- Sound is heard over longer distances on rainy days because sound travels faster in moist air.
- The speed of sound in a medium is inversely proportional to the square root of its density. Therefore, the speed of sound in moist air is more than that in dry air.
- Railway tracks are banked on curves so that necessary centripetal force may be obtained from the horizontal component of the normal reaction due to track.
- We feel cool when we sit near the fan, this is because air vaporises the sweat on our body.
- The average kinetic energy of the molecules of an ideal gas is directly proportional to absolute temperature of the gas.
- At boiling point of liquids , its temperature remains constant.
- On a clean glass plate a drop of water spreads to form a thin layer whereas a drop of mercury remains almost spherical because Cohesion of mercury is greater than its adhesion with glass.
- Glass is an insulator.
- Due to Surface Tension bubbles from liquid are formed.
- The boiling point of water depends upon the atmospheric pressure.
- Lux meter is used to measure the intensity of light.
- The phenomenon which established the transverse nature of light is Polarisation.
- Rectifier is used to convert alternating current into direct current.
- Ice covered in sawdust not melt quickly because sawdust is a bad conductor of heat.
- The washing machine works on the principle of Centrifugation.
- The ‘Choke’ used with a tube light is basically an inductor.
- Temperature of distant luminous bodies can be determined by Pyrometers.
- Energy travels from Sun to Earth through radiation.
- Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in convection.
SSC CGL Physics - Points:
- Transistor is used as an amplifying device.
- The unit of measurement of noise is Decibel.
- A galvanometer can be converted into a voltmeter by connecting with it a high resistance on series.
- During Idle running of an automobile, carbon monoxide content in exhaust gas is maximum.
- An eudiometer measures volume of gases.
- The Beaufort scale is used to measure wind velocity.
- The component used for tuning a radio is basically a variable condenser.
- 0°K is equivalent to -273°C.
- Addition of suitable impurities into semiconductor, is called Doping.
- The absolute zero is a temperature at which molecular motion in a gas would cease.
- The instrument used for measuring air pressure is called Barometer.
- Intensity of any wave is proportional to square of amplitude.
- Water is used in a hot water bag because it has high specific heat.
- The temperature of a liquid is 32° F. its temperature in Celsius scale is 0° C.
- The point where total mass of a body is supposed to be concentrated is known as centre of mass.
- Electrical charges in a charged conductor reside at the outer surface of the body.
- The colour of the ocean appears to be blue because the sunlight falling on it is scattered.
- X-Ray
- Binary Number System, Decimal Number System and BCD Number System are weighted code.
- In the absence of the earth’s atmosphere, sky would appear black.
- i. Travel with the speed of light.
ii. Can be reflected or refracted.
iii. Can affect photographic plates.
SSC CGL Physics - Points:
- When a car is moving around a curve, centripetal force acts on it.
- The phenomenon responsible for the echo of sound wave is reflection.
- Silver has the maximum thermal conductivity among iron, silver, aluminium and copper.
- Wind energy is the cleanest source of energy among bio-fuel, fossil fuel, nuclear power and wind energy.
- Temperature of distant luminous bodies can be determined by Pyrometers.
- A pyrometer is a type of remote-sensing thermometer used to measure the temperature of a surface.
- If electric resistance is to be decreased, then the number of resistances should be connected in parallel.
- The material used in electric heater is nichrome.
- Silver is an ohmic conductor.
- Anemometer is an instrument meant for measuring wind speed.
- The spring balance works on the principle of Hook’s law.
- The liberation of oxygen during photosynthesis is due to photolysis of water.
- Process responsible for the glittering of air bubble rising through water is total internal reflection of light.
- In an optical fibre the signal is transmitted due to total internal reflection.
- Sun appears red in colour at sunrise and sunset due to all other colours scatter away except red.
- At hill stations, the boiling point of water will be less than that at sea level.
- Dakshin Gangotri is unmanned station located in Antarctica.
- Reverse Osmosis is the treatment of water pollution.
- When we see an object, the image formed on the retina is real and inverted.
- Kinetic energy depends on both mass and velocity of the moving body.
SSC CGL Physics - Points:
- Kinetic energy is the supplied heat energy stored during change in temperature of substance.
- Transformer is a device to convert low voltage A.C. into high voltage A.C.
- The weight of an object is maximum on the poles of the earth.
- Quality of a musical instrument is depends on harmonic present.
- A galvanometer can be converted to a voltmeter by connecting a high resistance in series.
- The frequency of direct current is zero.
- The reverse effect of X-ray emission is photo-electric effect.
- The photoelectric effect or photo ionization is the emission of electrons or other free carriers when light is shone onto a material. Electrons emitted in this manner can be called photo electrons.
- One of the common forms of representing remote sensing data as information is in the form of thematic maps.
- The group of solar cells joined together in a definite pattern is called a solar cell panel.
- Photo Electric Effect to take place, the metal used as the cathode should have low work function.
- Spectroheliograph is used for photographing the Sun.
- The spectroheliograph is an instrument used in astronomy which captures a photographic image of the Sun at a single wavelength of light, a monochromatic image. The wavelength is usually chosen to coincide with a spectral wavelength of one of the chemical elements present in the Sun.
- Fuse wire is made of an alloy of tin and lead.
- The fuse element is made of zinc, copper, silver, aluminium, or alloys to provide stable and predictable characteristics. The fuse ideally would carry its rated current indefinitely, and melt quickly on a small excess.
- Visible light has the lowest frequency among the frequencies of gamma rays, X-rays, ultra violet rays and visible light.
- A fresh egg when placed in salt water will float.
- Flemings “Left Hand Rule” is associated with the effect of magnetic field on magnet.
- X-Ray, R-Ray, Cathode-Ray are electro-magnetic waves.
- The force which makes a vehicle to stop when break is applied is called frictional force.
SSC CGL Physics - Points:
- ‘Diodes’ are generally used for rectification.
- An anemometer measures speed of wind.
- Transformer cannot be developed within an ‘integrated circuit’.
- A particle is thrown vertically upward. When it reaches the highest point, it has a downward acceleration.
- The quality or tone of a musical sound produced by a stringed instrument depends on waveform of the sound.
- Every hot objects emits infrared rays.
- ‘Parsec’ is the unit measurement of astronomical distance.
- The phenomenon of change in direction of light when it passes from one medium to another is called refraction.
- A canon recoils after firing due to Newton’s third law of motion.
- A bomb explodes on the moon, one cannot hear the sound of explosion.
- In hydel power station, the motion produced in turbines is due to flow of water.
- Aditi Krishna Kumar in May 2016 won the prestigious 2016 Scholastic Asian Book Award for her work ‘Codex : The Lost Treasure of the Indus’.
- Super cooling stands for cooling of a liquid below freezing point.
- During the motion of a projectile fired from the earth surface, horizontal component of its velocity remains constant.
- Waves cannot be polarised is ultrasonic.
- Absolute Zero is defined as the temperature at which all molecular motion ceases.
- When ice cubes are made, the entropy of water decreases.
- Two vectors are said to be equal if both magnitude and direction are same.
- If speed of rotation of the earth increases, the weight of the body decreases.
- Electromagnet is constructed with soft iron.
SSC CGL Physics - Points:
- A body moving in a circular path with a constant speed has a constant kinetic energy.
- On a cold day when the room temperature is [latex]{15}^{0}[/latex]C the metallic cap of a pen becomes much colder than its plastic body, though both are at the same temperature of [latex]{15}^{0}[/latex]C , because metals are good conductors of heat.
- Copper wires are generally used for electrical power transmission instead of iron wire because copper is a better conductor of electricity than iron.
- Diamond does not conduct electricity, because no free electrons are present in it.
- Weightlessness experienced while orbiting the earth in space ships because of zero gravity.
- Sextant is an instrument used in navigation.
- If a healthy freshwater fish is placed in salt water, the fish becomes dehydrated and dies.
- Hertz, Decibel and Mach are associated with sound wave.
- If an electron and a photon have the same wavelength, then they will have the same linear momentum.
- The Gamma-rays has the highest frequency.
- Gamma rays are the highest energy EM radiation and typically have energies greater than 100 keV, frequencies greater than 1019 Hz, and wavelengths less than 10 picometers.
- The clear nights are cooler than the cloudy nights due to radiation.
- Mass of an object is:
- When a bus starts suddenly, then passengers in the bus tend to fall backwards. This event is an example of inertia of rest.
- Momentum of an object depends on mass and speed of the object.
- The main cause of energy radiated from sun is nuclear fusion.
- Nuclear fusion is a reaction in which two or more atomic nuclei come close enough to form one or more different atomic nuclei and subatomic particles (neutrons or protons).
- Jet engine works on the principal of conservation of linear momentum.
- Linear momentum is the product of the mass and velocity of an object. It is a three-dimensional vector quantity, possessing a direction and a magnitude.
- The level of water in a vessel remains same when a piece of ice floating in it melts.
- i. Physical Quantity
ii. Fundamental Quantity
iii. Scalar Quantity
SSC CGL Physics - Points:
- The mass is a measure of inertia.
- The instrument used to study the laws of vibrating string is sonometer.
- Quantities and their related SI Unit.
- Ability to distinguish two closely placed objects is resolving power.
- Radio waves are used for communication in artificial satellites.
- Multicasting is sending a frame to a group of stations.
- Electric motor was invented by Michael Faraday.
- A flying jet possesses both kinetic and potential energy.
- Direction of heat flow depends on temperature.
- The phenomenon of reflection is involved in Kaleidoscope.
- A kaleidoscope is an optical instrument with two or more reflecting surfaces inclined to each other in an angle.
- In a magnifying glass convex lens is used.
- When an object is kept between two parallel plane mirrors then the number of formed images will be infinite.
- Friction can be reduced by polishing surfaces and use of lubricants.
- Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other.
- When the speed of a moving object is halved, its kinetic energy becomes [latex]\frac{1}{4}[/latex] of the original.
- The working principle of a mercury thermometer is expansion of matter on heating.
- Action and reaction are equal in magnitude.
- The distance between a crest and a consecutive trough in a transverse wave is half of the wavelength.
| Quantities | SI Unit |
|---|---|
| Frequency | Hertz |
| Force | Newton |
| Resistance | Ohm |
| Energy | Joule |
| Power | Watt |
SSC CGL Physics - Points:
- The most suitable unit for expressing nuclear radius is Fermi.
- Maxwell is the unit of magnetic flux.
- The ‘Law of Gravitation’ was given by Isaac Newton.
- Law of Inertia is also known as Newton’s first law of motion.
- Newton’s first law states that an object will remain at rest or move at a constant speed in a straight line unless it is acted on by an unbalanced force.
- When surface water of a lake is about to freeze, the temperature of water at the bottom of the lake will be 10°C.
- Electric energy is produced during conversion of solar energy using photovoltaic cell.
- Hydraulic brakes used in automatic vehicles are direct virtual application of Pascal’s law.
- Germanium is widely used in making semiconductor chips.
- The first law of thermodynamics is related to conservation of energy.
- The law of conservation of energy states that the total energy of an isolated system is constant, energy can be transformed from one form to another, but can be neither created nor destroyed.
- Nichrome is used in the manufacturing of electric heater coil.
- Moon’s gravitation = [latex]\frac{1}{6}^{th}[/latex] of Earth’s gravitation.
- The force of attraction between an electron revolving around the nucleus and the nucleus is an electric force.
- Silver has the highest electrical conductivity.
- In fluid mechanics, if the speed of an object is equal to the speed of sound then Mach number is 1.
- The Mach number (M or Ma) is a dimensionless quantity representing the ratio of flow velocity past a boundary to the local speed of sound.
- Law of Conservation of Electric Charge was discovered by Benjamin Franklin.
- Water converts to water vapour at 373 K.
- The unit of frequency is Hertz.
SSC CGL Physics - Points:
- Electric current is measured by Ammeter.
- Sounds of frequencies below 20 Hz are called infrasonic sound.
- Concave mirror is used by dentists to see large images of teeth.
- When resistors are connected in series, then net resistance increases.
- Frictional force is responsible for changing the state of motion of an object.
- Frictional Force refers to the force generated by two surfaces that contacts and slide against each other. These forces are mainly affected by the surface texture and amount of force impelling them together.
- According to law of reflection, angle of incidence is always equal to angle of reflection.
- The law of reflection states that the incident ray, the reflected ray, and the normal to the surface of the mirror all lie in the same plane. Furthermore, the angle of reflection is equal to the angle of incidence.
- There is no unit of relative density.
- Relative density is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity usually means relative density with respect to water.
- Archimedes principle states that when a body is immersed fully or partially in a fluid, it experiences an upward force that is equal to the weight of the fluid displaced by it.
- Laser was invented by T. H. Maiman.
- The units of speed are m/s, km/hr and cm/s.
- ‘Laws of motion’ was given by Newton.
- The force acting on an object perpendicular to the surface is called thrust.
- Thrust is a reaction force described quantitatively by Newton's second and third laws. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction on that system.
- Unit of speed is meter per second (m/s), unit of density is kilogram per cubic metre (kg/[latex]{m}^{3}[/latex]) and unit of acceleration is meter per second squared (m/[latex]{s}^{2}[/latex]).
- Tensiometer is used to measure Soil Water Tension.
- The SI unit of Force is Newton.
- Aluminium, copper and silver is a good Thermal Conductor.
SSC CGL Physics - Points:
- The minimum distance required to hear an echo is 17 meter.
- A black board appears black in colour because it absorbs all the colours.
- X-rays was discovered by W. C. Roentgen.
- Meter in a vehicle that calculates distance covered by the vehicle is called odometer.
- The SI unit of pressure is Pascal.
- Reflection from a smooth surface like that of a mirror is called regular reflection.
- The unit of resistance is ohm.
- The other name of Galileo’s law of falling bodies is Newton’s first law.
- On the basis of the law of parabolic fall, Galileo reached the conclusion that bodies fall on the surface of the earth at a constant acceleration, and that the force of gravity which causes all bodies to move downward is a constant force.
- An example of solid sol is coloured gemstones.
- Momentum, displacement and torque are vector quantity but speed is not a vector quantity.
- Dynamite was invented by Alfred Nobel.
- Acceleration, force and velocity are vector quantity but electric current is not a vector quantity.
- The phenomenon of raising the outer edge of the curved roads above the inner edge to provide necessary centripetal force to the vehicles to take a safe turn is called banking of roads.
- The bending of light when it passes around a corner or a slit is due to diffraction.
- It is difficult to fix a nail on a freely suspended wooden frame. This statement supports Newton’s third law.
- Newton’s third law is: For every action, there is an equal and opposite reaction.
- The property of electromagnetic waves are:
- Convex mirror is generally used in rear view mirror.
- The SI unit of frequency is Hertz.
- i. Oscillating electric field and magnetic field are perpendicular to each other.
ii. Electromagnetic waves are transverse waves.
iii. Electromagnetic waves do not show interference and diffraction.
SSC CGL Physics - Points:
- Speed of light is the maximum in vacuum.
- The SI unit of electric current is ampere.
- If objects appear enlarged and inverted in a rear view mirror, then concave mirror is used.
- Soap bubble attains spherical shape due to surface tension.
- A characteristic of an exothermic reaction is release of heat.
- Water tank appear shallower when viewed from the top due to refraction.
- An endothermic reaction is a reaction in which heat is absorbed.
- Weight of an object is the maximum at poles.
- The SI unit of temperature is Kelvin.
- Electric Motor converts electrical energy to mechanical energy.
- Optical fiber works on total internal reflection of the principle of light.
- The pitch of a sound is determined by frequency.
- The SI unit of intensity of sound is decibel.
- An Exothermic reaction is reaction in which heat is released.
- When a ball thrown vertically upwards energy remains constant during its motion.
- The SI unit of heat energy is Joule.
- Players must have the knowledge of Pascal’s law in scuba diving.
- The value of the Least Distance of Distinct vision for a normal human being is 25 cm.
- The hydraulic lift works on Pascal’s law.
- The numerical values on Celsius and Fahrenheit scales become equal at -400C.
SSC CGL Physics - Points:
- The theory of relativity was developed by Albert Einstein.
- The SI unit of Power is Watt.
- Units and their related quantity.
- Radar was invented by A. H. Taylor and Leo C. Young.
- If the orbit of the planet is elliptical, then the point at which the sun is situated is called the focus.
- The sliding friction is smaller than the static friction.
- Kelvin (K) is the unit of measurement of temperature.
- In science, a push or pull of an object is called force.
- The attribute cell spacing specifies (in pixels) the distance between two adjacent cells.
- In a qualitative way, the tendency of undisturbed objects to say at rest or to keep moving with the same velocity is called inertia.
- The time taken by a pendulum to complete one oscillation is called its time period.
- If the speed of an object moving along a straight line is constant, its motion is said to be uniform.
- The strength of a force is usually expressed by its magnitude.
- If the mass of an object is 60 kg, its weight on the moon will be 100N (N=Newton).
- The Moon only has [latex]\frac{1}{6}[/latex] the gravity that Earth does. This means you weigh six times less on the Moon than you do on Earth. (1 kg = 9.8 N.)
- The side mirrors of vehicles are convex mirrors.
- In the formula average velocity = [latex]\frac{(u + v)}{2}[/latex], u is the initial velocity.
- If the speed of an object moving along a straight line keeps changing, its motion is said to be nonuniform.
- The substances which reduce friction are called lubricants.
| Unit | Quantity |
|---|---|
| Parsec | Distance |
| Barrel | Liquid |
| Light Year | Time |
SSC CGL Physics - Points:
- The unit of calorific value is kJ/kg.
- If the force applied on the object is in the direction opposite to the direction of motion, the speed of the object decreases.
- The SI unit of acceleration is meters per seconds squared.
- Contact force is another name for muscular force.
- The force of friction between two surfaces will increase if the two surfaces are pressed harder.
- An image formed by a plane mirror, that cannot be obtained on a screen is called virtual image.
- The force exerted by a magnet is an example of non-contact force.
- The force which acts on an object without coming physically in contact with it is called non-contact force.
- According to the Second Law of Motion, for a given force, acceleration is inversely proportional to the mass of an object.
- The coil wire in the electric room heater or electric cooking heater is called element.
- Energy in the form of heat is wasted when a machine is operated. This heat is generated due to friction.
- The incident ray, the normal at the point of incident and the reflected ray all lie in the same plane.
- During uniform motion of an object along a straight line, the velocity remains constant with time.
- The impression of an image persists on the retina for about [latex]\frac{1}{16}^{th}[/latex] of a second.
- An image formed by a concave mirror on a screen is called real image.
- The distance-time graph for the motion of an object moving with a constant speed is a Straight Line.
- A nylon thread is actually stronger than a steel wire.
- If an object moves in a circular path with uniform speed, its motion is called uniform circular motion.
- The reflection formed by the plane mirror is lateral inversion.
- Convex and concave mirrors are examples of spherical mirrors.
SSC CGL Physics - Points:
- The frictional force exerted by fluids is also called drag.
- Benjamin Franklin discovered electricity and invented the lightning rod and bifocals.
- If the force applied on the object is in the direction of its motion, the speed of the object increases.
- The shape of the outer part of the ear is like a funnel.
- Friction is caused by the irregularities on the two surfaces in contact.
- The motion of a freely falling body is an example of uniformly accelerated motion.
- A ball rolling along the ground gradually slows down and finally comes to rest is due to friction.
- The angle between the normal and the incident ray is called the angle of incidence.
- For an object, the state of rest is considered to be the state of zero speed.
- The laws which govern the motion of planets are called Kepler’s Laws.
- The size of image formed is always equal to the size of object in plane mirror.
- I[latex]_{2}[/latex]R, VI and [latex]\frac{V_{2}}{R}[/latex] terms does represent electrical power in circuit.
- A positively charged particle projected towards west is deflected towards north by a magnetic field. The direction of magnetic field is upward.
- Alpha particle, proton and helium nucleus are positively charged but electron is negatively charged.
- Image formed is virtual, erect and point sized in convex mirror.
- Resistance is directly propotional to the length of the wire and inversely proportional to the cross sectional area of the Wire. As a wire gets longer its resistance increases and as it gets thinner its resistance also increases because its cross sectional area decreases.
- Force applied on the conductor depends on magnitude of current.
- A force is any interaction that, when unopposed, will change the motion of an object. A force can cause an object with mass to change its velocity, i.e., to accelerate.
- Force applied on the conductor depends on magnitude of magnetic field strength.
- The direction of heat flow between two bodies depends on their temperatures.
SSC CGL Physics - Points:
- In a concave mirror if object is placed at centre of curvature, then image will be at the centre of curvature.
- Fuse is generally placed in series with the device.
- A rectangular coil of copper wire is rotating in a magnetic field. The direction of the induced current changes once in each half revolution.
- Noise is measured in decibel.
- The splitting of white light into its component colours is called dispersion.
- Change in magnetic field produces induced current.
- Flow of current in a conductor produces magnetic field.
- Magnetic field related to coil can be produced by motion between conductor and coil.
- Hydrogen gas is used as a fuel in a rocket.
- Mercury, cadmium and Germanium is a good conductor Glass, on the other hand is an insulator.
- The phenomenon occurs due to refraction are:
- R[latex]_{1}[/latex] + R[latex]_{2}[/latex] will be equivalent resistance of two resistors R[latex]_{1}[/latex] and R[latex]_{2}[/latex] when connected in series.
- The phenomenon of electromagnetic induction is induced current in a coil due to relative motion between a magnet and the coil.
- Light waves are electromagnetic waves.
- The resistance of a metal conductor is directly proportional to its length.
- While moving from one end to another end inside a solenoid, its magnetic field remains same.
- Concave mirror would be best suited for use in a solar cooker.
- Silicon is semiconductor.
- Angle of incidence and angle of reflection are equal in case of plane mirror.
- Filament of electric bulbs are generally are made of tungsten.
- i. the apparent displacement of a pencil, partly immersed in water.
ii. sun appears before the sunrise.
SSC CGL Physics - Points:
- Fleming’s Right Hand Rule : movement of conductor, magnetic field and induced current are perpendicular to each other.
- Fahrenheit and Celsius scales are equal at the numerical value of temperature :–40°.
- Concave lens always forms a virtual, erect and diminished image.
- The direction of magnetic field lines in a magnet is North Pole to South Pole.
- Speed of a proton cannot change while it moves freely in magnetic field.
- Stethoscope works on reflection of sound principle.
- When the direction of motion of coil is perpendicular to the electromagnetic field, then the value of induced current is maximum.
- Horizontal heat transfer within a environment is called as advection.
- Time period of a pendulum will increases at the moon to that of on the Earth.
- Refractive angle is 90° for critical angle.
- Light ray goes from denser to rarer medium for critical angle.
- To hear a distinct echo, the time interval between the original sound and reflected sound must be atleast 0.1 seconds.
- Mercury, manganese and iron are the conductor of electricity whereas ebonite is not a conductor of electricity.
- An electric motor converts electric energy into mechanical energy.
- An electric generator works on the principle of electromagnetic induction.
- The magnetic field at the center of a long circular coil carrying current will be parallel straight lines.
- Virtual image is always formed by a convex mirror.
- There is a circular coil having n turns. The field produced is n times larger than produced by a coil of single turn.
- Atomic energy is not an example of a biomass energy source whereas wood, gobar gas and coal are the examples of biomass energy.
- Density of water decreases when it freezes.
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