## Class/Course - Engineering Entrance

### Subject - Physics

#### Total Number of Question/s - 3094

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• 1. Measurements - Quiz

1. The rad is the correct unit used to report the measurement of
a) The ability of a beam of gamma ray photons to produce ions in a target
b) The energy delivered by radiation to a target
c) The biological effect of radiation
d) The rate of decay of a radioactive source

2. Which of the following units denotes the dimensions [ML2/Q2], where Q denotes the electric charge?
a) Wb/m2
b) Henry (H)
c) H/m2
d) Weber (Wb)

• 2. Kinematics - Quiz

1. A small particle of mass m is projected at an angle θ with the x-axis with an intial velocity v0 in the x-y plane as shown in the figure. At a time t < $\frac{v_{0}sin\theta}{g}$, the angular momentum of the particles is

a) $-mgv_{0}t^{2} cos\theta \hat{j}$
b) $mgv_{0}t cos\theta \hat{k}$
c) $-\frac{1}{2}mgv_{0}t^{2}cos\theta\hat{k}$
d) $\frac{1}{2}mgv_{0}t^{2}cos\theta\hat{i}$

2. A particle is projected at 600 to the horizontal with a kinetic K. The kinetic energy at the highest point is
a) K
b) Zero
c) $\frac{K}{4}$
d) $\frac{K}{2}$

• 3. Laws of Motion - Quiz

1. A light string passing over a smooth light pulley connects two blocks of masses m1 and m2 (vertically). If the acceleration of the system is g/8, then the ratio of the masses is
a) 8 : 1
b) 9 : 7
c) 4 : 3
d) 5 : 3

2. Three identical blocks of masses m = 2 kg are drawn by a force F = 10.2 N with an acceleration 0f 0.6 ms-2 on a frictionless surface, then what is the tension (in N) in the string between the blocks B and C?

a) 9.2
b) 7.8
c) 4
d) 9.8

• 4. Work, Energy and Power - Quiz

1. A 2 kg block slides on a horizontal floor with a speed of 4 m/s. It strikes a uncompressed spring, and compresses it till the block is motionless. The kinetic friction is 15 N and spring constant is 10000 N/m. The spring compresses by
a) 5.5 cm
b) 2.5 cm
c) 11.0 cm
d) 8.5 cm

2. At time t = 0 s particle starts moving along the x-axis. If its kinetic energy increases uniformly with time t, the net force acting on it most be proportional to
a) $\sqrt{t}$
b) Constant
c) t
d) $\frac{1}{\sqrt{t}}$

• 5. Rotational Motion - Quiz

1. A solid sphere is rotating in free space. If the radius of the sphere is increased keeping mass same, which one of the following will not be affected?
a) Moment of interia
b) Angular momentum
c) Angular velocity
d) Rotational kinetic energy

2. A particle performing uniform circular motion has angular momentum L. If its angular frequency is doubled and its kinetic energy halved, then the new angular momentum is
a) $\frac{L}{4}$
b) 2 L
c) 4 L
d) $\frac{L}{2}$

• 6. Gravitation - Quiz

1. Suppose the gravitational force varies inversely as the nth power of distance. Then the time period of a planet in circular orbit of radius R around the sun will be proportional to
a) $R^{\left (\frac{n + 1}{2} \right )}$
b) $R^{\left (\frac{n - 1}{2} \right )}$
c) Rn
d) $R^{\left (\frac{n - 2}{2} \right )}$

2. If g is the acceleration due to gravity on the earth surface, the gain in the potential energy of an object of mass m raised from the surface of the earth to a height equal to the radius R of the earth, is
a) 2 mgR
b) $\frac{1}{2}mgR$
c) $\frac{1}{4}mgR$
d) mgR

• 7. Properties of Solids and Liquids - Quiz

1. If S is stress and Y is Youngs modulus of material of a wire, the energy stored in the wire per unit volume is
a) 2S2Y
b) $\frac{S^{2}}{2Y}$
c) $\frac{2Y}{S^{2}}$
d) $\frac{S}{2Y}$

2. A 20 cm long capillary tube is dipped in water. The water rises upto a 8 cm. If the entire arrangement is put in a freely falling elevator, the length of water column in the capillary tube will be
a) 8 cm
b) 10 cm
c) 4 cm
d) 20 cm

• 8. Thermodynamics - Quiz

1. When a system is taken from state I to state f along the path iaf, it is found that Q = 50 cal and W = 20 cal. Along the path ibf, Q = 36 cal. W along the path ibf is

a) 6 cal
b) 16 cal
c) 66 cal
d) 14 cal

2. A carnot engine operating between temperatures T1 and T2 has efficiency $\frac{1}{6}$. When T2 is lowered by 62 K its efficiency increases to$\frac{1}{3}$. Then T1 and T2 are, respectively
a) 372 K and 330 K
b) 330 K and 268 K
c) 310 K and 248 K
d) 372 K and 310 K

• 9. Kinetic Theory of Gases - Quiz

1. An insulated container of gas has two chambers seperated by an insulating partition. One of the chambers has volume V1 and contains ideal gas at pressure p1 and temperature T2. If the partition is removed without doing any work on the gas, the final equilibrium temperature of the gas in the container will be
a) $\frac{T_{1}T_{2}\left ( p_{1}V_{1} + p_{2}V_{2} \right )}{p_{1}V_{1}T_{2} + p_{2}V_{2}T_{1}}$
b) $\frac{p_{1}V_{1}T_{1} + p_{2}V_{2}T_{2}}{p_{1}V_{1} + p_{2}V_{2}}$
c) $\frac{p_{1}V_{1}T_{2} + p_{2}V_{2}T_{1}}{p_{1}V_{1} + p_{2}V_{2}}$
d) $\frac{T_{1}T_{2}\left ( p_{1}V_{1} + p_{2}V_{2} \right )}{p_{1}V_{1}T_{1} + p_{2}V_{2}T_{2}}$

2. Three perfect gases at absolute temperatures T1, T2 and T3 are mixed. The masses of molecules are m1, m2 and m3 and the number of molecules are n1, n2 and n3 respectively . Assuming no loss of energy, the final temperature of the mixture is
a) $\frac{n_{1}T_{1} + n_{2}T_{2} + n_{3}T_{3}}{n_{1}+ n_{2} + n_{3}}$
b) $\frac{n_{1}T_{1}^{2} + n_{2}T_{2}^{2} + n_{3}T_{3}^{2}}{n_{1}T_{1}+ n_{2}T_{2} + n_{3}T_{3}}$
c) $\frac{n_{1}^{2}T_{1}^{2} + n_{2}^{2}T_{2}^{2} + n_{3}^{2}T_{3}^{2}}{n_{1}T_{1}+ n_{2}T_{2} + n_{3}T_{3}}$
d) $\frac{\left ( T_{1} + T_{2} + T_{3} \right )}{3}$

• 10. Oscillations and Waves - Quiz

1. In forced oscillation of a particle, the amplitude is maximum for a frequency $\omega _{1}$ of the force, while the energy is maximum for a frequency $\omega _{2}$of the force, then
a) $\omega _{1}$=$\omega _{2}$
b) $\omega _{1}$>$\omega _{2}$
c) $\omega _{1}$<$\omega _{2}$ when damping is small and
$\omega _{1}$<$\omega _{2}$ when damping is large
d) $\omega _{1}$<$\omega _{2}$

2. Statement I Two longitudinal waves given by equations -y1 (x,t) = 2a sin(ω - kx) and y2(x,t) = asin(2ωt - 2kx) will have equal intensity.
Statement II Intensity of waves of given frequency in same medium is proportional to square of amplitude only.
a) Statement I is false, Statement II is true
b) Statement I is true, Statement II is false
c) Statement I is true, Statement II true; Statement II is the correct explanation of Statement I
d) Statement I is true, Statement II is true; Statement II is not correct explanation of Statement I

• 11. Electrostatics - Quiz

1. Combination of two identical capacitors, a resistor R and a DC voltage source of voltage 6V is used in an experiment on C-R circuit. It is found that for a parallel combination of the capacitor the time in which the voltage of the fully charged combination reduces to half its original voltage is 10s. For series combination the time needed for reducing the voltage of the fully charged series combination by half is
a) 20 s
b) 10 s
c) 5 s
d) 2.5 s

2. An electric charge +q moves with velocity $\vec{v}$ = $3\hat{i} + 4\hat{j} + \hat{k}$ ,in an electromagnetic field given by $\vec{E}$ = $3\hat{i} + \hat{j} + 2\hat{k}$, $\vec{B}$ = $\hat{i} + \hat{j} - 3\hat{k}$. The y component of the source experienced by +q is
a) 2q
b) 11q
c) 5q
d) 3q

• 12. Current Electricity - Quiz

1. In the circuit, the galvanometer G shows zero deflection. If the batteries A and B have negligible internal resistance, the value of the resistor R will be

a) 200 Ω
b) 100 Ω
c) 500 Ω
d) 1000 Ω

2. The resistance of hot tungsten filament is about 10 times the cold resistance. What will be the resistance of 100W and 200 V lamp, when not in use?
a) 40Ω
b) 20Ω
c) 400Ω
d) 200Ω

• 13. Magnetic Effects of Current and Magnetism - Quiz

1. The magnetic field due to a current carrying circular loop of radius 3 cm at a point on the axis at a distance of 4 cm from the centre is 54μT. What will will be its value at the centre of the loop?
a) 250μT
b) 150μT
c) 125μT
d) 75μT

2. If an electron and a proton having same momenta enter perpendicularly to a magnetic field, then
a) curved path of electron and proton will be same (ignoring the sense of revolution)
b) they will move undeflected
c) curved path of electron is more curved than that of proton
d) path of proton is more curved

• 14. Electromagnetic Induction and Alternating Current - Quiz

1. In a series L-C-R circuit R = 200Ω and the voltage and the frequency of the main supply is 220V and 50Hz respectively. On taking out the capacitance from the circuit lags behind the voltage by 300. The power dissipated in the L-C-R circuit is
a) 305W
b) 210 W
c) zero
d) 242 W

2. An inductor (L = 100 mH), a resistor (R = 100Ω) and a battery (E = 100V) are initially connected in series as shown in the figure. After a long time the battery is disconnected after short circulating the points A and B. The current in the circuit 1 ms after the short circuit is

a) 1/eA
b) eA
c) 0.1A
d) NAB ω

• 15. Electromagnetic Waves - Quiz

1. The rms value of the electric field of the light coming from the sum is 720 NC-1. The average total energy density of the electromagnetic wave is
a) 4.58 x 10-6 Jm-3
b) 6.37 x 10-19 Jm-3
c) 81.35 x 10-12 Jm-3
d) 3.3 x 10-3 Jm-3

2. A radiation of energy E falls normally on a perfectly reflecting surface. The momentum transferred to the surface is
a) $\frac{E}{c}$
b) $\frac{2E}{c}$
c) Ec
d) $\frac{E}{c^{2}}$

• 16. Optics - Quiz

1. An astronomical telescope has a large aperture to
a) reduce spherical aberration
b) have high resolution
c) increase span of observation
d) have low dispersion

2. A beaker contains water up to a height h1 and kerosene of height h2 above water so that the total height of (water + kerosone) is (h1 + h2). Refractive index of water is μ1 and that of kerosene is μ2. The aparent shift in the position of the bottom of the beaker when viewed from above is
a) $\left (1 - \frac{1}{\mu_{1}} \right )h_{2} + \left (1 - \frac{1}{\mu_{2}} \right )h_{1}$
b) $\left (1 + \frac{1}{\mu_{1}} \right )h_{1} + \left (1 + \frac{1}{\mu_{2}} \right )h_{2}$
c) $\left (1 - \frac{1}{\mu_{1}} \right )h_{1} + \left (1 - \frac{1}{\mu_{2}} \right )h_{2}$
d) $\left (1 + \frac{1}{\mu_{1}} \right )h_{2} - \left (1 + \frac{1}{\mu_{2}} \right )h_{1}$

• 17. Dual Nature of Matter and Radiation - Quiz

1. Two identical photocathodes receive light of frequencies f1 and f2 If the velocities of the photoelectrons (of mass m) coming out are respectively v1 ans v2 then
a) $v_{1}^{2} - v_{2}^{2}$ = $\frac{2h}{m}\left (f_{1} - f_{2} \right )$
b) $v_{1} + v_{2}$ = $\left [\frac{2h}{m}\left (f_{1} + f_{2} \right ) \right ]^{1/2}$
c) $v_{1} - v_{2}$ = $\left [\frac{2h}{m}\left (f_{1} - f_{2} \right ) \right ]^{1/2}$
d) $v_{1} - v_{2}$ = $\left [\frac{2h}{m}\left (f_{1} - f_{2} \right ) \right ]^{1/2}$

2. Wave property of electrons implies that they will slow diffraction effects. Davisson and Germer demonstrated this by diffracting effects .Davisson and Germer demonstrated this by diffracting electrons from crystal. The law governing the diffraction from a crystal is obtained by requiring that electron waves reflected from the planes of atoms in a crystal interfere construtively (see figure)

If a strong diffraction peak is observed when electrons are incident at an angle I from the normal to the crystal planes with distance d between them (see figure), de-Broglie wavelength λdB of electrons can be calculated by the relationship (n is an integer)
a) d sin I = nλdB
b) 2d cos I = nλdB
c) 2d sin I = nλdB
d) d cos I = nλdB

• 18. Atoms and Nuclei - Quiz

1. Statement I A nucleus having having energy E1 decays be β- emission to daughter nucleus having energy E2, but the β- rays are emitted with a continuous energy spectrum having end point energy E1 - E2.
Statement II To conserve energy and momentum in β-decay at least three particles must take part in the transformation.
a) Statement I is false, Statement II is true
b) Statement I is true, Statement II is true
c) Statement I is true, Statement II is true; Statement II is the correct explanation of Statement I
d) Statement I is true, Statement II is true; Statement II is not the correct explanation of Statement I

2. A nucleus with Z = 92 emits the following in a sequence:
$\alpha,\alpha, \beta^{-},\beta^{-},\alpha,\alpha,\alpha,\alpha;\beta^{-},\beta^{-},\alpha,\beta^{+},\beta^{+},\alpha$
The Z of the resulting nucleus is
a) 76
b) 78
c) 82
d) 74

• 19. Electronic Devices - Quiz

1. When npn transistor is used as an amplifier
a) electrons move from base to collector
b) holes move from either to base
c) electrons move from collector to base
d) holes move from base to emiiter

2. At absolute zero, Si acts as
a) non-metal
b) metal
c) insulator
d) None of these

• 20. Communication Systems - Quiz

1. The logic circuit shown below has the input waveforms A and B as shown. Pick out the correct output wavefrom.

a)
b)
c)
d)

2. This question has statement 1 and statement 2. Of the four choices given after the statements, choose the one that best describes the two statements.
Statement 1. Sky wave signals are used for long distance radio communication. These signals are in general, less stable than ground wave signals.
Statement 2 The state of ionosphere varies from hour to hour, day to day and season to season.
a) Statement 1 is true, Statement 2 is true, Statement 2 is the correct explanation of Statement 1
b) Statement 1 is true , Statement 2 is true, Statement 2 is not the correct explanations of Statement 1
c) Statement 1 is false, Statement 2 is true
d) Statement 1 is true, Statement 2 is false