1.Rain drops acquire spherical shape due to
a) viscosity
b) surface tension
c) friction
d) elasticity
Answer: Option (b)
Explanation:
The Surface tension pulls the surface of the drop equally at all points thus produces the spherical shape having the minimum surface area.
2. It is more difficult to walk on ice than on a concrete road because
a) there is very little friction between the ice and feet pressing it
b) ice is soft when compared to concrete
c) there is more friction between the ice and feer
d) None of these
Answer: Option (a)
Explanation:
It is the friction between the feet and the ground that helps us to walk. Without this friction we would slip and fall.
3. A solid ball of metal has a spherical cavity inside it. When the ball is heated the volume of the cavity will
a) increase
b) decrease
c) remain unaffected
d) have its shape changed
Answer: Option (a)
Explanation:
The metal ball can be considered to be made up of several layers of thinner ones. On heating each of these layers will increase in radius. As the inner most layer also increases its radius, the volume inside it i.e, the volume of the hollow portion will also increase.
4. When a bottle of perfume is opened in one corner of a room the smell spreads soon throughout the room. This is an example of
a) surface tension
b) capillarity
c) viscosity
d) diffusion
Answer: Option (a)
Explanation:
Diffusion is the spreading - mixing of gases through molecular motion.
5. Skating on ice is possible because
a) the surface of ice is smooth
b) ice is cold
c) the pressure on the ice due to skate melts the ice by lowering its melting point forming a thin film of water
d) the pressure on the ice due to skate raises its melting point
Answer: Option (c)
Explanation:
Here is a case of lowering of melting point of ice with increase of pressure
6. A bucket of water is hung from a spring balance. A piece of iron is suspended in the water without touching the sides or touching the bottom of the bucket. The reading of the spring balance
a) will increase
b) will decrease
c) does not change
d) varies with the increase of depth of the immersion of the iron piece
Answer: Option (a)
Explanation:
When the piece of iron is lowered into the water, the water level in the bucket increases. And so the pressure at the bottom of bucket also increases. Thus the total thrust at the botto also increases. Therefore the spring balance reading increases.
7. Pieces of camphor placed on water move about rapidly. This is because of
a) diffusion
b) viscosity
c) surface tension
d) capillarity
Answer: Option (c)
Explanation:
The Camphor slowly dissolves in the water lowering the latter's surface tension in the immediate neighbourhood. The stronger pull exerted by the uncontaminated portion of water brings about a movement of the surface and the camphor particles are carried along with it. When after sometime the whole surface settles for the reduced tension, the movement of the camphor too short.
8. If a band is played on the moon the sound will
a) reverberate
b) be heard by us faintly
c) be heard upto 10km from it
d) not be heard at any distance at all from it
Answer: Option (d)
Explanation:
As there is no atmosphere surrounding the moon, the sound from any band that is played there cannot travel outwards there is no material medium surrounding it for its propagation.
9. Formation of shadows can be explained by
a) rectilinear propagation of light
b) reflection
c) refraction
d) total internal reflection
Answer: Option (a)
Explanation:
In this position, the head light will be at the principal focus so that the rays of light falling on the cancave mirror will be rendered parallel
10. The base of an electric iron is brightly polished mainly
a) to make it smooth and frictionless
b) to make it rust-proof
c) to reduce heat loss by radiation
d) to make it more durable
Answer: Option (c)
Explanation:
Polished surfaces are poor radiators of heat. So loss of heat on that account is reduced and the electric iron remains hotter than otherwise.
11. What is newton third law of motion?
a) Every body maintains its initial state rest or motion unless no external force is applied.
b) The rate of change in momentum of a body is directly proportional to the applied force on the body and takes place in the direction of force.
c) To every action there is equal and opposite reaction.
d) None of above.
Answer: Option (c)
Explanation:
Newton First Law of Motion: Every body maintains its initial state rest or motion unless no external force is applied.
Newton Second Law of Motion: The rate of change in momentum of a body is directly proportional to the applied force on the body and takes place in the direction of force.
12. If no external force acts on a system of bodies, the total linear momentum of the system of bodies remains constant. Which law states this?
a) Newton first law
b) Newton second law
c) Newton third law
d) Principle of conservation of linear momentum
Answer: Option (d)
Explanation:
Principle of conservation of linear momentum states If no external force acts on a system of bodies, the total linear momentum of the system of bodies remains constant.
13. Energy posses by a body in motion is called
a) Kinetic Energy
b) Potential Energy
c) Both of Above
d) None of Above
Answer: Option (a)
Explanation:
Energy posses by a body in motion is called Kinetic Energy.
14. If lift is going up with acceleration, the apparent weight of a body is
a) may be more or less than true weight
b) equal to the true weight
c) less than the true weight
d) more than the true weight
Answer: Option (d)
Explanation:
If lift is going up with acceleration, the apparent weight of a body is more than the true weight.
15. What is escape velocity?
a) Escape velocity is the maximum velocity with which a body should be projected from the surface of earth so it do not go beyond gravitational field of earth.
b) Escape velocity is the minimum velocity with which a body should be projected from the surface of earth so it do not go beyond gravitational field of earth.
c) Escape velocity is the minimum velocity with which a body should be projected from the surface of earth so as it goes out of gravitational field of earth and never return to earth.
d) Escape velocity is the maximum velocity with which a body should be projected from the surface of earth so as it goes out of gravitational field of earth and never return to earth.
Answer: Option (c)
Explanation:
Escape velocity is the minimum velocity with which a body should be projected from the surface of earth so as it goes out of gravitational field of earth and never return to earth.
16. Sudden fall in barometer is indication of
a) Storm
b) Rain
c) Tide
d) Clear weather
Answer: Option (a)
Explanation:
Sudden fall in barometer is indication of Storm.
17. The force which opposes the relative motion between different layers of liquid or gases is called
a) Critical Velocity
b) Streamline Flow
c) Terminal Velocity
d) Viscous Force
Answer: Option (d)
Explanation:
Critical Velocity - The maximum velocity upto which fluid motion is streamline is called Critical Velocity.
Streamline Flow - If velocity of all fluid particles is same all the time then it can be said in streamline flow.
Terminal Velocity - When a body falls in viscous medium, its velocity first increases and finally becomes constant. The constant velocity is called terminal velocity.
18. What is the maximum value of deforming force upto which a material shows elastic property and above which the material loses it?
a) Elasticity
b) Strain
c) Elastic Limit
d) Stress
Answer: Option (c)
Explanation:
The Maximum Extent to which a solid may be stretched without permanent alteration of size or shape.
19. What is Hooke's Law?
a) Stress is inversely proportional to strain.
b) Stress is directly proportional to strain.
c) Stress and strain are dependent on each other.
d) Stress and strain are independent of each other.
Answer: Option (b)
Explanation:
Hooke's law is a principle of physics that states that the force (F) needed to extend or compress a spring by some distance X scales linearly with respect to that distance.
20. Lognitudinal waves and Transverse waves are types of?
a) Mechanical waves
b) Non-Mechanical waves
c) Both of above
d) None of Above
Answer: Option (a)
Explanation:
Mechanical Waves are waves which propagate through a material medium (solid, liquid, or gas) at a wave speed which depends on the elastic and inertial properties of that medium. There are two basic types of wave motion for mechanical waves: longitudinal waves and transverse waves.
21. What is the relation between wavelength, frequency and velocity?
a) velocity of wave = frequency * wavelength
b) velocity of wave = frequency/wavelength
c) velocity of wave = wavelength/frequency
d) None of above
Answer: Option (a)
Explanation:
That number, also known as the frequency, will be larger for a short-wavelength wave than for a long-wavelength wave. The equation that relates wavelength and frequency for electromagnetic waves is: c = ν*λ where λ is the wavelength, ν is the frequency and c is the Velocity of wave.
22. What are audible sound waves?
a) Having frequency less than 20 Hz
b) Having frequency between 20 Hz to 20000 Hz
c) Having frequency more than 20000 Hz
d) None of above
Answer: Option (b)
Explanation:
Human ear can easily detect frequencies between 20 Hz and 20 KHz. Hence sound waves with frequency ranging from 20 Hz to 20 KHz are known are audible sound. The human ear is sensitive to every minute pressure difference in the air if they are in the audible frequency range.
23.What is the range of mercury thermometer?
a) 0 degree Celsius to 350 degree Celsius
b) -10 degree Celsius to 350 degree Celsius
c) -20 degree Celsius to 350 degree Celsius
d) -30 degree Celsius to 350 degree Celsius
Answer: Option (d)
Explanation:
Mercury thermometers cover a wide temperature range from −30 to 350 °C the instrument's upper temperature range may be extended though the introduction of an inert gas such as nitrogen.
24. Which law states, "The rate of loss of heat by a body is directly proportional to the difference in temperature between the body and the surroundings."
a) Doppler's Effect
b) Newton's law of cooling
c) Kirchhoff's Law
d) Stefan's Law
Answer: Option (b)
Explanation:
Doppler's Effect - The Doppler effect can be described as the effect produced by a moving source of waves in which there is an apparent upward shift in frequency for observers towards whom the source is approaching and an apparent downward shift in frequency for observers from whom the source is receding.
Kirchhoff's Law - Kirchhoff's Law signifies that good absorbers are good emitters.
Stefan's Law - The radiant energy emitted by a black body per unit area per unit time is directly proportional to the fourth power of its absolute temperature.
25. The nuclear reaction in which a heavy nucleus splits into two nuclei of nearly equal mass is called
a) Nuclear fusion
b) Nuclear fission
c) Nuclear reaction
d) Fast breeding
Answer: Option (b)
Explanation:
Nuclear fission is a process used to create energy. It is when an atom splits apart into smaller atoms. The process gives off a lot of energy, and is used in nuclear weapons and nuclear reactors. Nuclear fission was discovered in December 1938 by the German nuclear chemist Otto Hahn and his assistant Fritz Strassmann in Berlin.
26. Which unit we use to express nuclear sizes?
a) Tesla
b) Newton
c) Fermi
d) None of above
Answer: Option (c)
Explanation:
A unit of length used to measure nuclear sizes, is Fermi.
27.The mass of an electron in motion depends upon:
a) direction of motion
b) B its velocity
c) C its velocity of e-
d) D it's shell number
Answer: Option (b)
Explanation:
The electron has a mass that is approximately 1/1836 that of the proton.[10] Quantum mechanical properties of the electron include an intrinsic angular momentum (spin) of a half-integer value, expressed in units of the reduced Planck constant, ħ. As it is a fermion, no two electrons can occupy the same quantum state, in accordance with the Pauli Exclusion Principle.
28. Rain drops acquire spherical shape due to
a) viscosity
b) surface tension
c) friction
d) elasticity
Answer: Option (b)
Explanation:
The Surface tension pulls the surface of the drop equally at all points thus produces the spherical shape having the minimum surface area.
29. Light year is a unit of
a) time
b) distance
c) light
d) intensity of light
Answer: Option (b)
Explanation:
Light year is a unit of distance
30. Light from the Sun reaches us in nearly
a) 2 minutes
b) 4 minutes
c) 8 minutes
d) 16 minutes
Answer: Option (c)
Explanation:
The sun's light takes about 8 minutes to reach the Earth after it has been emitted from the sun's surface. The time it takes for light to reach planets in our Solar System (not the Milky Way, which is our galaxy) varies from about 3 minutes for Mercury, to about 5.3 hours for Pluto
31. Stars appears to move from east to west because
a) all stars move from east to west
b) the earth rotates from west to east
c) the earth rotates from east to west
d) the background of the stars moves from west to east
Answer: Option (b)
Explanation:
Earth's spin (or rotation) on its axis. Earth rotates or spins toward the east, and that's why the Sun, Moon, planets, and stars all rise in the east and make their way westward across the sky.
32. Planets do not twinkle because
a) they emit light of a constant intensity
b) their distance from the earth does not change with time
c) they are very far away from the earth resulting in decrease in intensity of light
d) they are nearer to earth and hence we receive a greater amount of light and, therefore minor variations in the intensity are not
noticeable
Answer: Option (d)
Explanation:
Planets are just like the Sun, do not twinkle. Planets are also closer to the Earth than those distant stars, so planets appear larger in comparison. Due to the planets' closeness to Earth, the light coming from these celestial bodies does not bend much due to Earth's atmosphere
33. Metals are good conductors of electricity because
a) they contain free electrons
b) the atoms are lightly packed
c) they have high melting point
d) All of the above
Answer: Option (a)
Explanation:
Copper is used for electrical wiring because it is a good conductor of electricity. Metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points. The free electrons in metals can move through the metal, allowing metals to conduct electricity.
34. If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same
a) velocity
b) momentum
c) acceleration
d) kinetic energy
Answer: Option (b)
Explanation:
If two bodies of different masses, initially at rest, are acted upon by the same force for the same time, then the both bodies acquire the same momentum
35. Rectifiers are used to convert
a) Direct current to Alternating current
b) Alternating current to Direct current
c) high voltage to low voltage
d) low voltage to high voltage
Answer: Option (b)
Explanation:
Converting DC power from one voltage to another is much more complicated. One method of DC-to-DC conversion first converts power to AC (using a device called an inverter), then uses a transformer to change the voltage, and finally rectifies power back to DC.
36. Magnetism at the centre of a bar magnet is
a) minimum
b) maximum
c) zero
d) minimum or maximum
Answer: Option (c)
Explanation:
The field at the center is not zero, but weak. At the exact center of a magnet the field lines are parallel (straight lines if we draw it). Any where else they are slightly divergent.
37. Of the following properties of a wave, the one that is independent of the other is its
a) amplitude
b) velocity
c) wavelength
d) frequency
Answer: Option (a)
Explanation:
The maximum extent of a vibration or oscillation, measured from the position of equilibrium.
38. Lux is the SI unit of
a) intensity of illumination
b) luminous efficiency
c) luminous flux
d) luminous intensity
Answer: Option (a)
Explanation:
The SI unit of intensity of illumination (illuminance) is the lux. An illuminance of 1.0 lux is produced by 1.0 lumen of light shining on an area of 1.0 m^2.
39. On a rainy day, small oil films on water show brilliant colours. This is due to
a) dispersion
b) interference
c) diffraction
d) polarization
Answer: Option (b)
Explanation:
The combination of two or more electromagnetic waveforms to form a resultant wave in which the displacement is either reinforced or cancelled.
40. If electrical conductivity increases with the increase of temperature oIf a substance, then it is a:
a) Conductor
b) Semiconductor
c) Insulator
d) Carborator
Answer: Option (b)
Explanation:
A solid substance that has conductivity between that of an insulator and that of most metals, either due to the addition of an impurity or because of temperature effects
41. With the increase of pressure, the boiling point of any substance
a) Increases
b) Decreases
c) Remains Same
d) Becomes zero
Answer: Option (a)
Explanation:
The temperature stays the same until all the liquid has vaporized. As the temperature of a liquid rises, the pressure of escaping vapor also rises, and at the boiling point the pressure of the escaping vapor is equal to that exerted on the liquid by the surrounding air, causing bubbles to form.
42. Elecronegativity is the measure of
a) Metallic character
b) Non-metallic character
c) Basic Character
d) None of these
Answer: Option (b)
Explanation:
Electronegativity cannot be directly measured and must be calculated from other atomic or molecular properties. Several methods of calculation have been proposed, and although there may be small differences in the numerical values of the electronegativity, all methods show the same periodic trends between elements.
43. The rotational effect of a force on a body about an axis of rotation is described in terms of the
a) Centre of gravity
b) Centripetal force
c) Centrifugal force
d) Moment of force
Answer: Option (d)
Explanation:
The rotational effect of a force on a body about an axis of rotation is described in terms of the Moment of force
44. If no external force acts on a system of bodies, the total linear momentum of the system of bodies remains constant. Which law states that?
a) Newton's first law
b) Newton's Second Law
c) Newton's Third Law
d) Principle of conservation of linear momentum
Answer: Option (d)
Explanation:
Conservation of linear momentum. The principle that the linear momentum of a system has constant magnitude and direction if the system is subjected to no external force. Also called law of conservation of linear momentum
45. Air pressure is usually highest when the air is
a) warm and moist
b) cool and dry
c) warm and dry
d) cool and moist
Answer: Option (d)
Explanation:
Both warmth and moisture reduce the density of air and hence its pressure.
46. In a freezer ice cubes will be formed more quickly in trays made of
a) rubber
b) plastic
c) aluminium
d) wood
Answer: Option (c)
Explanation:
Aluminium being a good conductor of heat conducts away the heat from the substance quite easily and causes quick freezing.
47. The information of brilliant colors in a thin soap film is a consequence of the phenomena of
a) Polarization and interference
b) Diffraction and dispersion
c) Multiple refraction and dispersion
d) Multiple reflection and interference
Answer: Option (d)
Explanation:
Light waves reflected by the upper and lower boundaries of a thin film interfere with one another, either enhancing or reducing the reflected light.
48. The ringing of an electric bell in an enclosed evacuated glass bell jar is not heard outside because
a) the ringing is not loud enough
b) the glass of the bell jar absorbs the sound waves
c) the bell jar is too small
d) there is no air or any other gas in the bell jar
Answer: Option (d)
Explanation:
As there is no medium inside the bell jar, sound cannot travel
49. A man jumping out of a moving train is thrown
a) forward
b) backward
c) sidewaqys
d) None of these
Answer: Option (a)
Explanation:
At the time of jumping out he has the same velocity as the moving train
50. Which is best used as a sound absorbing material in partition walls?
a) Stone chips
b) Steel
c) Glass - wool
d) Glass pieces
Answer: Option (c)
Explanation:
Materials that do not transfer mechanical energy well. These tend to be soft,flexible, low density, and with high surface area to linear area ratios.
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