physics mcq with answers

physics mcq with answers
MCQ on Physics objective Multiple choice questions Answer
Simple physics multiple choice questions

1. Radio waves of wavelength 360 m are transmitted from a transmitter. The inductance of the coil which must be connected with a capacitor of capacity 1.2 micro F in a resonant circuit to receive these waves will be approximately:
(a) 103H
(b) 102H
(c) 10-4H
(d) 10-8 H
Ans. (d)

2. Match List-I with List-II and select the correct answer using the codes given below the Lists:
List-I List-II
A. Hall effect 1. Transverse difference of
temperature when current flows
at right angles to magnetic field.
B. Nernst and 2. Transverse difference of
Ettinghausen effect temperature when heat flows at
right angles, to the, magnetic field.
C. Ettinghausen effect 3. Transverse emf when heat flows
at right angles to the magnetic field.
D. Leduc effect 4. Transverse emf when current flows at right angles to the magnetic field.
Codes:
A B C D
(a) 4 1 3 2
(b) 4 3 1 2
(c) 2 3 1 4
(d) 2 1 3 4
Ans. (a)


3. In a mass spectrometer, the velocity filter employs electric field E and a perpendicular magnetic field B. The deflecting magnetic field perpendicular to the beam is B. Ions with similar charges q and mass numbers m1 and m2 pass through the filter. After a 1800 turn in the deflecting field, the separation between them will be:
(a) E(m2 –m1)/ qBB’
(b) 2E(m2 –m1)/ qBB’
(c) Eq(m2 –m1)/ BB’
(d) 2qE(m2 –m1)/ BB’
Ans. (b)

4. The emf of a thermocouple, one junction of which is at 0° C is given by
E = at + bt2
The Peltier coefficient is given by (T is in Kelvin):
(a) T(2at + b)
(b) T(2a + bt)
(c) T(a + bt)
(d) T(a + 2bt)
Ans. (d)

5. A cyclotron having segments of radius 50 cm is used for accelerating hydrogen nuclei. The polarity of the segments is reversed 5 x 107 times/s. The energy of the incoming proton beam is (mass of the proton = 1.673 x 10-24 g; 1.6x 10-12erg =1eV)
(a) 3.225 MeV
(b) 32.25MeV
(c) 3225MeV
(d) 0.3 225 MeV
Ans. (b)

6. A copper disc of 10 cm radius makes 1200 rev/mm with its plane perpendicular to a magnetic field. If the induced emf between the centre and edge of the disc is 6.28 mV, then the intensity of the field is
(a) 100 oersted
(b) 80 oersted
(c) 60 oersted
(d) 50 oersted
Ans. (a)



7. An electron (mass= me) and a proton (mass= lB36 me) are moving with the same speed. The ratio of their de-Broglie wavelengths λelectron/λproton will be:
A proton
(a) 1
(b) 1836
(c) 1/1836
(d) 918
Ans. (b)

8. A hydrogen-like atom has a i meson of mass 200 times that of an electron, bound to the proton. The radius of the first Bohr orbit of this muonic atom will be:
(a) Equal to that of H
(b) 10 times that of H
(c) 200 times that of H
(d) 1/200 times that of H
Ans. (d)

9. If the mass of a particle is that times its rest mass, then the speed at which the particle is moving is (c = velocity of light):
(a) (?8/3) c
(b) (?8/9) c
(c) (8/9) c
(d) 3c
Ans. (b)

10. The beta decay of the neutron is explicitly given by:
(a) n —> p + e
(b) n —> p + e + vs
(c) n —> p + e +
(d) n —> p + e + ?
Ans. (c)


11. The particle ?- was predicted in 1963 as a member of the Baryon decouplet and discovered in 1964. Its spin J, isospin I and strangeness quantum number S are:
J I S
(a) ½ 0 -1
(a) 3/2 1 -2
(a) 3/2 0 -3
(a) 3/2 0 +3
Ans. (a)

12. Given that’
Eb1 = 250V at Ec1 = 50V,
Eb2 =180V at Ec2 = - 30V
and plate current being kept the same, the ? of a triode is:
(a) 6
(b) 5
(c) 3.5
(d) 5.5
Ans. (c)

13. Pure silicon is simultaneously doped with boron to a concentration of 1020 atoms per cubic centimeter and with phosphorus to a concentration of 7 x ió atoms per cubic centimeter. The number 41 holes per unit volume of silicon will be approximately:
(a) 1020
(b) 17 x 1019
(c) 7 x 1019
(d) 3 x 1019
Ans. (a)

14. Match List-I with List II arid select the correct answer using the codes given below the Lists.
List-I List-II
A. Emitter-base junction current 1. Drift current.
B. Base current 2. Diffusion current
C. Emitter-Collector current 3. Recombination current
D. Base-Collector junction current
Codes:
A B C D
(a) 1 2 3 1
(b) 1 3 2 1
(c) 2 3 3 2
(d) 3 2 3 1
Ans. (c)

15. The relative humidity in a room is 5% at 15°C. What will be the relative humidity if the temperature increased by 10°C?
(SVP at 15°C = 12.38mm of Hg
SVP at 25°C 24.76mm of Hg)
(a) 1.25%
(b) 2.5%
(c) 5%
(d) 10%
Ans. (b)

16. One mole of a perfect gas expands adiabatically. As a result of this, its pressure, temperature and volume change from P1. T1, V1 to P2, T2 and V2 respectively. If molar specific heat at constant volume is CV, then the work done by the as is:
(a) 2.303 P1 V1 log(V2/V1)
(b) RT1 log(V2/V1)
(c) (P12V12 - P22V22) / R(T2 – T1)
(d) CV(T1 – T2)
R(T2-T1)
Ans. (d)

17. Match List L (Physical quantity) with List II (Units) an select the correct answer using the codes given below the Lists:
List I List II
A. Mass 1. Slug
B. Torque 2. Poise
C. Impulse 3. Newton second
D. Viscosity 4. Newton meter
5. Newton
Codes:
A B C D
(a) 1 4 3 2
(b) 5 4 2 1
(c) 1 5 3 2
(d) 5 2 4 1

Ans. (a)

18. A 2 kg mass is acted upon by a force which gives a time t dependent displacement of x = t2/2 the work done in the time interval 0 to t0 is
(a) 0.5t0
(b) t0
(c) t02
(d) t03
Ans. (c)

19. A sphere of radius R and mass M rolls without slipping on a surface with speed v. The ratio of translational KE and rotational KE is:
(a) 1/5
(b) 2/5
(c) 5/2
(d) 5
Ans. (c)

20. Match List I (Conservation law) with List II (Associated symmetries) and select the correct answer using the codes given below the Lists:
List I List II
A. Energy 1. Homogeneity of space
B. Linear momentum 2. Isotropy of space
C. Angular momentum 3. Homogeneity of time
Codes:
A B C
(a) 3 2 1
(b) 1 2 3
(c) 3 1 2
(d) 2 1 3
Ans. (c)


21. The force needed to punch a hole of diameter 7 cm in a steel plate of thickness 2/? cm and ultimate shear strength of 350 X 106 Nm-2 is
(b) 9.8 x 105N
(d) 68.6 x 105N
(a) 4.9 x 105N
(c) 34.3 x 105N
Ans. (a)


22. Particle A has a velocity of 2 x 108 m/s and another particle B has a velocity of - 2 x 108 m/s. The velocity of A relative to B is:
(a) 4 x 108m/s
(b) Zero
(c) 2.76 x 108 m/s
(d) 1.38 x 108 m/s
Ans. (c)


23. Match List I (Property of fluid) with List II (Law of fluid motion) and select the correct answers using the codes given below the Lists:
List I List II
A. Volume rate of flow 1. Bernoulli’s theorem
B. Viscous drag 2. Torricelli’s theorem
C. Speed of efflux (exit) 3. Stoke’s law
D. Pressure difference 4. Poiseuille’s law
between two points
in a flow tube
Codes:
A B C D
(a) 4 3 1 2
(b) 3 4 1 2
(c) 3 4 2 1
(d) 4 3 2 1
Ans. (c)

24. A drop of water is placed between two glass plates (assume that the glass plates are of negligible weight) on a table. The drop of water flattens into a film of thickness d=10-6 m and area 8 x 10-4m2.
If the surface tension of water is 70 x 10-3Nm-1, then the force required to lift the top plate (clearly separating it from the bottom plate) will be:
(a) 224N
(b) 112N
(c) 56 N
(d) 2.24 x 10-12 N
Ans. (b)

25. Two lenses of dispersive powers of 0.01 and 0.02 can form an achromatic doublet only when the ratio of their focal lengths is:
(a) ?2:1
(b) 2:1
(c) -2:1
(d) 1:-2
Ans. (d)