# MCQs / Compilation of Physics Problems Part 4 MCQs / Compilation of Physics Problems
PRACTICE TEST IN PHYSICS SET 4

1. When a rolling solid cylinder reaches the bottom of the slope, its linear velocity is...
A. √ gh
B. √ 2gh
C. mgh
D. √(4gh/3)

2. For ideal gas, the graph of PV → P is...
A. a parabola
B. a hyperbola
C. inclined with P-axis
D. parallel to P-axis

3. A spherical drop of mercury has a diameter of 6.0 x 10-3 m. If the surface tention of mercury is 0.5 N/m, then the pressure inside the drop will exceed the pressure outside by about...
A. 42 Pa
B. 330 Pa
C. 167 Pa
D. 170 Pa

4. A lift attendant has a mass of 70 kg. When the lift is going up with a constant acceleration of 1 m/s2, the force acting upwards on him is...
A. zero
B. 70 N
C. 770 N
D. 700 N

5. A body is moved along a straight line by a machine delivering constant power. The distance moved by the body in time t is proportional to...
A. t1/2
B. t3/4
C. t3/2
D. t2

6. The angular velocity of a body is changed from ω1 to ω2 by changing its moment of inertia. If no torque acts on the body then the ratio of initial radius of gyration to the final radius of gyration is...
A. ω1 : ω2
B. ω2 : ω1
C. √ω1 : √ω2
D. √ω2 : √ω1

7. Two parallel plates carry opposite charges such that the electric field in the space betwen them is in upward direction. An electron is shot in the space and parallel to the plates. Its deflection from the original direction will be...
A. downwards
B. upwards
C. circular
D. none

8. Compton effect is associated to...
A. X-rays
B. β-rays
C. γ-rays
D. positive rays

9. If the magnitude of gravitational force is 1, the relative magnitude of strong force is...
A.  10-13
B.  10-38
C. 1038
D. 1013

10. In an elastic collision...
A. momentum is conserved but not kinetic energy
B. kinetic energy is conserved but not momentum
C. both momentum and kinetic energy are conserved
D. neither omentum nor kinetic energy is conserved

11. In a crystal the angles between the edges of the faces and between the faces themselves are...
A. right angles
B. acute angles
C. obtuse angles
D. constant

12. The equation of continuity indicates that the velocity of the fluid is greater at
A. narrow cross-section
C. entry point
D. exit point

13. The internal energy of an ideal gas is dependent on...
A. its temperature only
B. its temperature and volume
C. its temperature and pressure
D. its temperature, pressure and volume

14. The field at any point on the surface of the conductor is...
A. zero
B. parallel to the surface
C. perpendicular to the surface
D. neither parallel nor perpendicular to the surface

15. A magnetic iron bar is strongly heated. Its magnetic field...
A. becomes stronger
B. becomes weaker
C. reverses its direction
D. does not change

16. The angle subtended by the secondary bow at the eye is about...
A. 41°
B. 47°
C. 53°
D. 60°

17. If M and L are respectively the mass and luminosity of a star, then L = Mα, where...
A. 0<α<1
B. α<0
C. 1<α<2
D. 2<α<4

18. 'T' is period of oscillation of an object performing SHM. Its potential energy is zero at some instant. The time taken to attain maximum potential energy is...
A. T
B. T/2
C. T/4
D. T/8

19. A sonar signal sent vertically downwards from a ship is reflected from the ocean floor and detected by a microphone on the keel 0.4 s after transmissiom. If speed of sound in water is 1500 m/s, the depth of the ocean in metre is...
A. 150
B. 300
C. 600
D. 7500

20. A car of mass M is turning a corner of radius r. The coefficient of friction between the wheels and the horizontal road surface is μ. The maximum speed with which the car can turn the corner without skidding is given by...
A. Mrg
B. √Mrg
C. √ μrg
D. (μrM)/g

21. The altitude of geostationary satellite above the earth's surface is approximately...
A. 35900 km
B. 42300 km
C. 11.2 km
D. 24040 km

22. In order to emit electromagnetic radiation, an object must be at a temperature...
A. above 0 K
B. above 0°C
C. above that of its surroundings
D. high enough for it to glow

23. A 200 m long copper wire has a resistance of 2 ohm. Its cross-sectional area is ... (take ρ = 1.7 x 10-8 ohm-meter)
A.  0.0017 mm2
B. 1.7 mm2
C. 3.4 mm2
D. 5.3 mm2

24. The unit of conductivity is...
A. ohm-meter
B. ohm/meter
C. mho-meter
D. mho/meter

25. When the lead-storage cell is completely discharged, the specific gravity of the electrolyte becomes
A.  1.285
B.  1.825
C. 1.5
D. 1.15

26. Two solenoids A and B have equal number of turns. The length of A is twice that of B and the cross-sectional area of A is half that of B. Other things being similar, the ratio of their inductances LA/LB is equal to...
A. 1
B. 2
C. 4
D. 1/4

27. In a resistive circuit, the power factor is...
A. π
B. 1
C. √ 2
D.  √(1/2)

28. The impedance of a parallel RLC circuit at resonance is...
A. less than R
B. more than R
C. equal to R
D. any of the above

29. Longitudinal waves do not exhibit...
A. refraction
B. reflection
C. diffraction
D. polarization

30. If E1 is the energy of a photon of ultraviolet light and E2 that of a photon of red light, then...
A. E1/E2 = 1
B. E1 < E2
C. E1 > E2
D. E1 - E2 = 0