1.The numerical value of a given quantity is

A. independent of unit B. directly proportional to unit C. inversely proportional to unit D. directly proportional to the square root of the unit

Answer - Option C
2. The physical quantity which does not have the same dimensions as the other three is

A. spring constant B. surface energy C. surface energy D. acceleration due to gravity

Answer - Option D
3. Unit of reduction factor is

A. ampere B. ohm C. tesla D. weber

Answer - Option A
4. Lumen is the unit of

A. illuminating power B. luminous flux C. luminous intensity D. None of these

Answer - Option B
5. Which of the following quantities has units but not dimensions?

A. Displacement B. Angle C. Couple D. Speed

Answer - Option B

1. Bullet one is fired in the north direction with the muzzle velocity u. Find the velocity of the bullet as seen from the observer on the earth

A. u + v B. v - u C. u D. v

Answer - Option B
Explanation -Velocity of bullet w.r.t to train= − u Velocity of train = v Velocity of bullet w.r.t to train = Velocity of bullet w.r.t earth -Velocity of train w.r.t earth So Velocity of bullet w.r.t earth = Velocity of bullet w.r.t to train + Velocity of train w.r.t earth = − u + v = v−u
2. A train travels along a horizontal circular curve that has a radius of 200 m. If the speed of the train is uniformly increased from 30 km/h to 45 km/h in 5 s, determine the magnitude of the acceleration at the instant the speed of the train is 40 km/h.

A. a = 0.617 m/[latex]{s}^{2}[/latex] B. a = 1.037 m/[latex]{s}^{2}[/latex] C. a = 1.451 m/[latex]{s}^{2}[/latex] D. a = 0.833 m/[latex]{s}^{2}[/latex]

Answer - Option B
3. Calculate the rotational inertia of a wheel that has a kinetic energy of 13.2 kJ when rotating at 710 rev/min

A. 4.78kg B. 2.25kg C. 7.5kg D. None of these

Answer - Option A
Explanation -The wheel is rotating at a speed of N =710rpm Then the angular velocity of the rotating wheel is: ω = [latex]\frac {2πN}{60}[/latex] ω = [latex]\frac {2π × 710}{60}[/latex]=74.35 rad/s The kinetic energy of the wheel is E = 13.2 kJ = 13200 J [latex]\frac {1}{2}[/latex] I [latex]{ω}^{2}[/latex]=13200 [latex]\frac {1}{2}[/latex]I(74.35[latex]{(74.35)}^{2}[/latex]= 13200 I = [latex]\frac {2 × 13200}{{74.35}^{2}}[/latex]= 4.78 kg−[latex]{m}^{2}[/latex]
4. An airplane accelerates down a runway at 3.20 m/[latex]{s}^{2}[/latex] for 32.8 s until is finally lifts off the ground. Determine the distance traveled before takeoff.

A. 1720 m B. 2252 C. 1452 D. 1208

Answer - Option A
Explanation - a = +3.2 m/[latex]{s}^{2}[/latex]t = 32.8 s,vi = 0 m/s,d = ?? d = v x t + 0.5 xa x [latex]{t}^{2}[/latex] d = (0 m/s) x (32.8 s)+ 0.5 x (3.20 m/[latex]{s}^{2}[/latex])*(32.8[latex]{s}^{2}[/latex] ) d = 1720 m

5. When the motorcyclist is at A he increases his speed along the vertical circular parth at the rate of v = (0.3t)ft/[latex]{s}^{2}[/latex], where t is in seconds. If he starts from rest when he is at A, determine his velocity and acceleration when he reaches B.

A. v = 51.1 ft/, a[latex]{s}^{2}[/latex] = 9.83 ft/[latex]{s}^{2}[/latex] B. v = 51.1 ft/[latex]{s}^{2}[/latex], a = 8.18 ft/[latex]{s}^{2}[/latex] C. v = 51.1 ft/[latex]{s}^{2}[/latex], a = 10.31 ft/[latex]{s}^{2}[/latex] D. v = 51.1 ft/[latex]{s}^{2}[/latex], a = 8.69 ft/[latex]{s}^{2}[/latex]

Answer - Option C

1. A metre scale is moving with uniform velocity. This implies (a) the force acting on the scale is zero, but a torque about the centre of mass can act on the scale. (b) the force acting on the scale is zero and the torque acting about centre of mass of the scale is also zero. (c) the total force acting on it need not be zero but the torque on it is zero. (d) neither the force nor the torque need to be zero.

A. the force acting on the scale is zero, but a torque about the centre of mass can act on the scale. B. the force acting on the scale is zero and the torque acting about centre of mass of the scale is also zero. C. the total force acting on it need not be zero but the torque on it is zero D. neither the force nor the torque need to be zero.

Answer - Option B
2. A hockey player is moving northward and suddenly turns westward with the same speed to avoid an opponent. The force that acts on the player is

A. frictional force along westward B. muscle force along southward. C. frictional force along south-west. D. muscle force along south-west.

Answer - Option C
3. A body of mass 2kg travels according to the law x(t ) = pt + qt2 + rt3 where p = 3 [latex]{ms}^{-1}[/latex], q = 4 [latex]{ms}^{-2}[/latex] and r = 5 ms-3. The force acting on the body at t = 2 seconds is

A.136 N B.134 N C.158 N D.68 N

Answer - Option A
4. A ball is travelling with uniform translatory motion. This means that

A. it is at rest. B. the path can be a straight line or circular and the ball travels with uniform speed. C. all parts of the ball have the same velocity (magnitude and direction) and the velocity is constant. D. the centre of the ball moves with constant velocity and the ball spins about its centre uniformly.

Answer - Option C
5. Conservation of momentum in a collision between particles can be understood from

A. conservation of energy. B. Newton’s first law only. C. Newton’s second law only. D. both Newton’s second and third law.

Answer - Option C

1. A man squatting on the ground gets straight up and stand. The force of reaction of ground on the man during the process is

A. constant and equal to mg in magnitude. B. constant and greater than mg in magnitude. C. variable but always greater than mg. D. at first greater than mg, and later becomes equal to mg.

Answer - Option D
2. A raindrop falling from a height h above ground, attains a near terminal velocity when it has fallen through a height (3/4)h. Which of the diagrams shown in Fig. 6.8 correctly shows the change in kinetic and potential energy of the drop during its fall up to the ground?
Answer - Option B
3. A proton is kept at rest. A positively charged particle is released from rest at a distance d in its field. Consider two experiments; one in which the charged particle is also a proton and in another, a positron. In the same time t, the work done on the two moving charged particles is

A. same as the same force law is involved in the two experiments. B. less for the case of a positron, as the positron moves away more rapidly and the force on it weakens. C. more for the case of a positron, as the positron moves away a larger distance. D. same as the work done by charged particle on the stationary proton

Answer - Option C
4. A man squatting on the ground gets straight up and stand. The force of reaction of ground on the man during the process is

A. constant and equal to mg in magnitude. B. constant and greater than mg in magnitude. C. variable but always greater than mg. D. at first greater than mg, and later becomes equal to mg.

Answer - Option D
5. A body is falling freely under the action of gravity alone in vacuum. Which of the following quantities remain constant during the fall?

A.Kinetic energy. B.Potential energy. C.Total mechanical energy. D.Total linear momentum.

Answer - Option C

1. Find the angular acceleration of the cylinder about the axis passing through center of mass

A. [latex]\frac {a}{3r}[/latex] B.[latex]\frac {a}{4r}[/latex] C.[latex]\frac {a}{5r}[/latex] D. [latex]\frac {2a}{3r}[/latex]

Answer - Option D
Explanation -For the point of cylinder which comes in contact with plank, the acceleration should be should be same as plank acceleration [latex]\frac {1}{3}[/latex]a + Ra = ar α = [latex]\frac {2a}{3r}[/latex]
2. A nearly massless rod is pivoted at one end so it can freely swing as a pendulum. Two masses 2m and m are attached to it at distance a and 3a respectively from the pivot end. The rod is held horizontal and then released. Which of the following is correct?

A. The angular acceleration at the instant it is released [latex]\frac {5g}{11a}[/latex] B. Moment of inertia of the system about pivot is 11[latex]{ma}^{2}[/latex] C. The angular acceleration at the instant when the rod makes an angle θ with horizontal [latex]\frac {5gcosθ}{11a}[/latex] D.All are correct.

Answer - Option D
Explanation - Total torque about the pivot in horizontal position T =g(2a+3ma)=5mga Moment of Inertial about the pivot end I = 2[latex]{ma}^{2}[/latex] + 3[latex]{ma}^{2}[/latex] = 11[latex]{ma}^{2}[/latex] Now T = Iα rα=[latex]\frac {T}{I}[/latex] So α =[latex]\frac {5g}{11a}[/latex] Total torque about the pivot when the rod makes angle θ with horizontal T=g(2macosθ+3macosθ)=5mgacosθ So angular acceleration becomes α=[latex]\frac {5gcosθ}{11a}[/latex] When θ = 90 , torque becomes zero.
3. Find the frictional force acting on the cylinder

A. [latex]\frac {ma}{3}[/latex] B. [latex]\frac {ma}{2}[/latex] C. [latex]\frac {2ma}{3}[/latex] D. [latex]\frac {ma}{4}[/latex]

Answer - Option D
Explanation -From Ground frame of reference, frictional force is the only force acting on the cylinder So f = [latex]\frac {ma}{4}[/latex]
4. Find the Linear Momentum of the system just after the collision if ω is the angular velocity just after the collision

A. (mh+ML/2) ω B. (mh+ML) ω C. (mh+ML/3) ω D. None of these

Answer - Option A
Explanation - otal Linear momentum =Linear momentum of mass m + Linear momentum of the center of mass of the rod Now v = rω So v = hω and v = (L/2)ω So Total linear momentum =mh ω + M(L/2) ω =(mh+ML/2)ω
5. A particle of mass m is moving with a constant velocity along a line parallel to the +ve direction of the X-axis. The magnitude of its angular momentum w.r.t the origiN

A. Is zero B. Goes on increasing as x is increased C. Goes on decreasing as x is increased D. Remains constant for all positions of the particle

Answer - Option D

1. As observed from earth, the sun appears to move in an approximate circular orbit. For the motion of another planet like mercury as observed from earth, this would

A. be similarly true B. not be true because the force between earth and mercury is not inverse square law. C. not be true because the major gravitational force on mercury is due to sun. D. not be true because mercury is influenced by forces other than gravitational forces.

Answer - Option C
2. Satellites orbiting the earth have finite life and sometimes debris of satellites fall to the earth. This is because,

A. the solar cells and batteries in satellites run out. B. the laws of gravitation predict a trajectory spiraling inwards. C. of viscous forces causing the speed of satellite and hence height to gradually decrease. D. of collisions with other satellites.

Answer - Option C
3. Both earth and moon are subject to the gravitational force of the sun. As observed from the sun, the orbit of the moon

A. will be elliptical. B. will not be strictly elliptical because the total gravitational force on it is not central. C. is not elliptical but will necessarily be a closed curve. D. deviates considerably from being elliptical due to influence of planets other than earth.

Answer - Option B
4. Different points in earth are at slightly different distances from the sun and hence experience different forces due to gravitation. For a rigid body, we know that if various forces act at various points in it, the resultant motion is as if a net force acts on the c.m. (centre of mass) causing translation and a net torque at the c.m. causing rotation around an axis through the c.m. For the earth-sun system (approximating the earth as a uniform density sphere)

A. the torque is zero. B. the torque causes the earth to spin. C. the rigid body result is not applicable since the earth is not even approximately a rigid body. D. the torque causes the earth to move around the sun.

Answer - Option A
5. The earth is an approximate sphere. If the interior contained matter which is not of the same density everywhere, then on the surface of the earth, the acceleration due to gravity

A. will be directed towards the centre but not the same everywhere. B. will have the same value everywhere but not directed towards the centre. C. will be same everywhere in magnitude directed towards the centre. D. cannot be zero at any point

Answer - Option D

1. What is the term for the amount of disorder in a system?

A. Enthalpy B. Chaos C. Entropy D. Disequilibrium

Answer - Option C
2. A gas is compressed isothermally to half its initial volume. The same gas is compressed separately through an adiabatic process until its volume is again reduced to half. Then

A. Compressing the gas isothermally or adiabatic ally will require the same amount of work B. Which of the case (whether compression through isotherm or through adiabatic process) requires more work will depend upon the atomicity of the gas C. Compressing the gas isothermally will require more work to be done D. Compressing the gas through adiabatic process will require more work to be done

Answer - Option D
3. An ideal gas is compressed to half its initial volume by means of several processes. Which of the process results in the maximum work done on the gas?

A. Isothermal B. Adiabatic C. Isobaric D. Isochoric

Answer - Option B
4. The energy required to increase the temperature of one pound of water one degree Fahrenheit is known as a Btu. For what does this abbreviation stand?

A. Big Temperature Unit B. Brenwald’s Thermal Unit C. Britain Temperature Unification D. British Thermal Unit

Answer - Option D
5.A Carnot engine, having an efficiency of η =1/10 as heat engine, is used as a refrigerator. If the work done on the system is 10 J, the amount of energy absorbed from the reservoir at lower temperature is [AIPMT 2015]

A. 100 J B. 99 J C. 90 J D. 1 J

Answer - Option C

1. The temperature at which the r.m.s. velocity of H2 becomes escape velocity from the earth is,

A. 10059 °C B. 10059 K C. 10332 °C D. 10332 K

Answer - Option B
2. A molecule of mass m moving with a velocity v makes 5 elastic collisions with a wall of the container per second. The change in its momentum per second will be

A. mv B. 5 mv C. [latex]\frac {mv}{10}[/latex] D. 10mv

Answer - Option D
3. Speed of 3 molecules of a gas are 3 m/s, 4 m/s and 5 m/s. R.m.s. speed of these molecule is,

A. 4.8 m/s B. 4.08 m/s C. 4.5 m/s D. 4 m/s

Answer - Option B
4. What is the true for 3 moles of a gas?

A. 3 (Cp – Cv) = R B. [latex]\frac {Cp - Cv}{3}[/latex]= R C. Cp – Cv = R D. Cp – 3Cv = R

Answer - Option C
5. The internal energy of one mole of an ideal gas depend upon.

A. Volume of gas B. Temperature of gas C. Nature of gas D. Density of gas

Answer - Option B

1. The displacement of particle performing simple harmonic motion is given by, x = 8 sin wt + 6 cos wt, where distance is in cm and time is in second. The amplitude of motion is

A. 10 cm B. 14 cm C. 2 cm D. 3.5 cm

Answer - Option A
2. The length of second’s pendulum on the surface of earth is 1 m. the length of same pendulum on the surface of moon, where acceleration due to gravity is (1/6)th of the g on the surface of earth is

A. 36 m B. 1 m C. [latex]\frac {1}{63}[/latex] D. [latex]\frac {1}{6}[/latex]

Answer - Option D
3. A siren emitting a note of frequency n is fitted on a police van, traveling towards a stationary listener. What is the velocity of the van, if the frequency of he note heard by the listener is double the original frequency?

A. Vs = V B. Vs = [latex]\frac {v}{2}[/latex] C. Vs = 2V D. Vs = [latex]\frac {v}{3}[/latex]

Answer - Option B
4. Loudness of a note of sound is

A. Directly proportional to amplitude of the wave B. Directly proportional to square of amplitude of wave C. Directly proportional to velocity of the wave D. Directly proportional to square of velocity of the wave

Answer - Option B
5. Two wave having the intensities in the ratio of 9: 1 produce interference. The ratio of maximum to minimum intensity is equal to

A. 10 : 8 B. 9 : 1 C. 4 : 1 D. 2 : 1

Answer - Option C

1. A capacitor of 2 μF is charged as shown in the diagram. When the switch S is turned to position 2, the percentage of its stored energy dissipated is

A. 75% B. 80% C. 0% D. 25%

Answer - Option B
2. A parallel plate air capacitor of capacitance C is connected to a cell of emf V and then disconnected from it. A dielectric slab of dielectric constant K, which can just fill the air gap of the capacitor, is now inserted in it. Which of the following is incorrect?

A. The potential difference between the plates decreases K times B. The energy stored in the capacitor decreases K times C. The change in energy stored is [latex]\frac {1}{2}[/latex] [latex]{Cv}^{2}[/latex][latex]\frac {1}{2}[/latex]- 1 D. The charge on the capacitor is not conserved

Answer - Option D
3. Two charges, each equal to q, are kept at x = – a and x = a on the x-axis. A particle of mass m and charge q0 = q/2 is placed at the origin. If charge q0 is given a small displacement (y << a) along the y-axis, the net force acting on the particle is proportional to

A. Y B. -Y C.[latex]\frac {1}{Y}[/latex] D. - [latex]\frac {1}{Y}[/latex]

Answer - Option A
4. Two spherical conductors A and B of radii 1 mm and 2 mm are separated by a distance of 5 cm and are uniformly charged. If the spheres are connected by a conducting wire then in equilibrium condition, the ratio of the magnitude of the electric fields at the surface of spheres A and B is

A. 1:4 B. 1:2 C. 2:1 D. 4:1

Answer - Option D
5. Consider a neutral conducting sphere. A positive point charge is placed outside the sphere. The net charge on the sphere is then

A. Negative and distributed uniformly over the surface of the sphere B. Negative and appears only at the point on the sphere closest to the point charge C. Negative and distributed non-uniformly over the entire surface of the sphere D. Zero

Answer - Option D

1. The supply voltage to a room is 120 V. The resistance of the lead wires is 6 Ω. A 60 W bulb is already switched on. What is the decrease of voltage across the bulb, when a 240 W heater is switched on in parallel to the bulb?[JEE 2013]

A. Zero volt B. 2.9 volt C. 13.3 volt D. 10.04 volt

Answer - Option D
2. The temperature dependence of resistances of Cu and undoped Si in the temperature range 300-400 K, is best described by[JEE 2016]

A. Linear increase for Cu, exponential increase for Si B. Linear increase for Cu, exponential decrease for Si C. Linear decrease for Cu, linear decrease for Si D. Linear increase for Cu, linear increase for Si

Answer - Option B
3. Two large vertical and parallel metal plates having a separation of 1 cm are connected to a DC voltage source of potential difference X. A proton is released at rest midway between the two plates. It is found to move at 45° to the vertical JUST after release. Then X is nearly [JEE 2012]

A. 1 × [latex]{10}^{-5}[/latex] V B. 1 × [latex]{10}^{-7}[/latex] V C. [latex]{10}^{-9}[/latex]V D. 1 × [latex]{10}^{-10}[/latex] V

Answer - Option C
4. In a large building, there are 15 bulbs of 40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1 kW. The voltage of the electric mains is 220 V. The minimum capacity of the main fuse of the building will be :[JEE 2012]

A. 10A B. 12A C. 14A D. 8A

Answer - Option B
5. A heater coil is cut into two equal parts and only one part is now used in the heater. The heat generated will now be

A. doubled B. four times C. one fourth D. halved

Answer - Option A

1. A galvanometer of resistance 50 Ω gives a full scale deflection for a current 5 × [latex]{10}^{-4}[/latex] A. The resistance that should be connected in series with the galvanometer to read 3 V is

A. 5059 Ω B. 595 Ω C. 5950 Ω D. 5050 Ω

Answer - Option C
2. A circular loop of radius 0.3 cm lies parallel to a much bigger circular loop of radius 20 cm. The centre of the small loop is on the axis of the bigger loop. The distance between their centres is 15 cm. If a current of 2.0 A flows through the smaller loop, then the flux linked with bigger loop is

A. 9.1 × [latex]{10}^{-11}[/latex]weber B. 6 × [latex]{10}^{-11}[/latex]weber C. 3.3 × [latex]{10}^{-11}[/latex]weber D. 6.6 × [latex]{10}^{-9}[/latex]weber

Answer - Option A
3. This question has Statement I and Statement II. Of the four choices given after the Statements, choose the one that best describes the two Statements. [JEE Main 2013]
Statement – I : Higher the range, greater is the resistance of ammeter.
Statement – II : To increase the range of ammeter, additional shunt needs to be used across it.

A. Statement - I is true, Statement - II is true, Statement - II is the correct explanation of Statement-I. B. Statement - I is true, Statement - II is true, Statement - II is not the correct explanation of Statement-I. C. Statement - I is true, Statement - II is false. D. Statement - I is false, Statement - II is true.

Answer - Option D
4. A charged particle moves through a magnetic field perpendicular to its direction. Then

A. the momentum changes but the kinetic energy is constant B. both momentum and kinetic energy of the particle are not constant C. both momentum and kinetic energy of the particle are constan D. kinetic energy changes but the momentum is constant

Answer - Option A
5. A galvanometer having a coil resistance of 100 Ω gives a full scale deflection, when a current of 1 mA is passed through it. The value of the resistance, which can convert this galvanometer into ammeter giving a full scale deflection for a current of 10 A, is [

A. 2 Ω B. 0.1 Ω C. 3 Ω D. 0.01 Ω

Answer - Option D

1. In a series RL circuit, the resistance and inductive reactance are the same. Then the phase difference between the voltage and current in the circuit is

A. π/4 B. π/2 C. π/6 D. zero

Answer - Option A
2. In a series resonant RLC circuit, the voltage across 100 Ω resistor is 40 V. The resonant frequency ω is 250 rad/s. If the value of C is 4 µF, then the voltage across L is

A. 600 V B. 4000 V C. 400V D. 1 V

Answer - Option C
3. .The flux linked with a coil at any instant t is given by ΦB = 10t 2 − 50t + 250. The induced emf at t = 3s is

A. −190 V B. −10 V C. 10 V D. 190 V

Answer - Option B
4. When the current changes from +2A to −2A in 0.05 s, an emf of 8 V is induced in a coil. The co-efficient of self-induction of the coil is

A. 0.2 H B. 0.4 H C. 0.8 H D. 0.1 H

Answer - Option D
5. In a transformer, the number of turns in the primary and the secondary are 410 and 1230 respectively. If the current in primary is 6A, then that in the secondary coil is

A. 2A B. 18A C. 12A D. 1A

Answer - Option A

1. Arrange the following electromagnetic radiations per quantum in the order of increasing energy: [JEE Mains 2016] A : Blue light B : Yellow light C : X-ray D : Radiowave

A. A, B, D, C B. C, A, B, D C. B, A, D, C D. D, B, A, C

Answer - Option D
2. Out of the following options which one can be used to produce a propagating electromagnetic wave?

A. A chargeless particle B. An accelerating charge C. A charge moving at constant velocity D. A stationary charge

Answer - Option B
3. A red LED emits light at 0.1 watt uniformly around it. The amplitude of the electric field of the light at a distance of 1 m from the diode is [JEE Mains 2015]

A. 1.73 V/m B. 2.45 V/m C. 5.48 V/m D. 7.75 V/m

Answer - Option B
4. During the propagation of electromagnetic waves in a medium:

A. Electric energy density is half of the magnetic energy density. B. Electric energy density is equal to the magnetic energy density. C. Both electric and magnetic energy densities are zero. D. Electric energy density is double of the magnetic energy density.

Answer - Option B
5. Absorption of X-Rays is maximum in which one of the following material sheets of the same thickness?

A. Cu B. Au C. Be D. Pb

Answer - Option D

1. When a metallic surface is illuminated with radiation of wavelength λ, the stopping potential is V. If the same surface is illuminated with radiation of wavelength 2 λ, the stopping potential is 4/V. The threshold wavelength for the metallic surface is

A. 5/2 λ B. 3 λ C. 4 λ D. 5 λ

Answer - Option B
2. Photons with energy 5 eV are incident on a cathode C in a photoelectric cell. The maximum energy of emitted photoelectrons is 2 eV. When photons of energy 6 eV are incident on C, no photoelectrons will reach the anode A, if the stopping potential of A relative to C is

A. +3 V B. +4 V C. –1 V D. –3 V

Answer - Option D
3. The de Broglie wavelength of an electron accelerated to a potential of 400 V is approximately

A. 0.03 nm B. 0.04 nm C. 0.12 nm D. 0.06 nm

Answer - Option D
4. A photon of energy 10.2 eV collides inelastically with a Hydrogen atom in ground state. After a certain time interval of few micro seconds another photon of energy 15.0 eV collides inelastically with the same hydrogen atom, then the observation made by a suitable detector is

A. 1 photon with energy 10.2 eV and an electron with energy 1.4 eV B. 1 photon with energy 10.2 eV and an electron with energy 1.4 eV C. 2 photon with energy 1.4 eV D. one photon with energy 3.4 eV and 1 electron with energy 1.4 eV

Answer - Option A
5. According to Einstein’s photoelectric equation, the plot of the kinetic energy of the emitted photoelectrons from a metal Vs the frequency, of the incident radiation gives a straight line whose slope:

A. depends on the nature of the metal used B. depends on the intensity of the radiation C. depends both on the intensity of the radiation and the metal used D. is the same for all metals and independent of the intensity of the radiation

Answer - Option D

1. A photon of energy 10.2 eV collides inelastically with a Hydrogen atom in ground state. After a certain time interval of few micro seconds another photon of energy 15.0 eV collides inelastically with the same hydrogen atom, then the observation made by a suitable detector is

A. 1 photon with energy 10.2 eV and an electron with energy 1.4 eV B. 2 photon with energy 10.2 eV C. 2 photon with energy 1.4 eV D. one photon with energy 3.4 eV and 1 electron with energy 1.4 eV

Answer - Option A
2. The work function of metals is in the range of 2 eV to 5eV. Find which of the following wavelength of light cannot be used for photoelectric effect. (Consider, Planck constant = 4 × [latex]\frac {10}{-15}[/latex] eVs, velocity of light = 3 × [latex]\frac {10}{8}[/latex]m/s)

A. 510 nm B. 650 nm C. 400 nm D. 570 nm

Answer - Option B
3. Light of wavelength ‘λ’ which is less than threshold wavelength is incident on a photosensitive material. If incident wavelength is decreased so that emitted photo electrons are moving with same velocity then stopping potential will

A. increase B. decrease C. be zero D. become exactly half

Answer - Option A
4. The de-Broglie wavelength ‘λ’ of a particle

A. is proportional to mass B. is proportional to impulse C. is inversely proportional to impulse D. does not depend on impulse

Answer - Option C
5. If the kinetic energy of a free electron doubles, its de Broglie wavelength changes by the factor

A. 2 B. 1/2 C. √2 D. 1/√2

Answer - Option D

1. Atoms and Nuclei Class 12 MCQ Question 1. When a β-particle is emitted from a nucleus then its neutron-proton ratio

A. increases B. decreases C. remains unchanged. D. may increase or decrease depending upon the nucleus.

Answer - Option B
Explanation - In P-decay neutron converts to proton with emission of electron and neutrino.
2. A radioactive nucleus emits a beta particle. The parent and daughter nuclei are

A. isotopes B. isotones C. isomers D. isobars

Answer - Option D
Explanation - Isobars have the same atomic mass but 1 different atomic number.
3. The radius of a spherical nucleus as measured by electron scattering is 3.6 fm. What is the mass number of the nucleus most likely to be?

A. 27 B. 40 C. 56 D. 120

Answer - Option A
4.Energy produced in sun is due to .

A. Motion of electrons and ion B. Chemical reaction C. Fusion reaction D. Fission reaction

Answer - Option C
5. The quantity which is not conserved in a nuclear reaction is

A. momentum B. charge C. mass D. none of these

Answer - Option C
Explanation - Energy equivalent to mass detect is released.

1. If a, b, c, d are inputs to a gate and x is its output, then, as per the following time graph, the gate is:

A. AND B. OR C. OR D. OR

Answer - Option B
2. For CE transistor amplifier, the audio signal voltage across the collector resistance of 2 kΩ is 4 V. If the current amplification factor of the transistor is 100 and the base resistance is 1 kΩ, then the input signal voltage is

A. 10 mV B. 20 mV C. 30 mV D. 15 mV

Answer - Option B
3. A transistor is operated in common emitter configuration at constant collector voltage Vc = 1.5 V such that a change in the base current from 100 μA to 150 μA produces a change in the collector current from 5 mA to 10 mA. The current gain (β) is:

A. 67 B. 67 C. 100 D. 50

Answer - Option C
4. The intrinsic carrier concentration in silicon is to be no greater than ni = 1 x 10^12 cc. The maximum temperature allowed for the silicon is

A. 300 K B. 360 K C. 382 K D. 364 K

Answer - Option C
5. A capacitor holds 0.03 C of charge when fully charged by a 6V battery. To hold 2C of charge, the voltage required would be

A. 150V B. 100V C. 300V D. 400V

Answer - Option D

1. A modem is classified as low speed if data rate handled is

A. upto 100 bps B. upto 250 bps C. upto 250 bps D. upto upto 250 bps600 bps

Answer - Option D
Explanation - When data rate in bits per second is upto 600, modem is low speed.
2. A woofer should be fed from the input through a

A. low pass filter B. high pass filter C. band pass filter D. band stop filter

Answer - Option A
Explanation - Woofer is a low frequency loud speaker covering the range 16 Hz to 500 Hz.
3. In transistor radio receivers the number of IF amplifier stages are

A. 1 B. 2 C. 4 D. 6

Answer - Option B
Explanation -Two IF amplifier stages are very commonly used.
4. To relay outdoor remotely located live programs, TV transmitter use

A. microwave links B. coaxial cable link C. open wire link D. either (b) or (c)

Answer - Option A
Explanation - Microwave links are used.
5. The most commonly used transistor amplifier circuit is

A. CB B. CC C. CE D. CE or CC

Answer - Option C
Explanation - Common emitter connection has high power gain, and good current and voltage gains.