# Competitive Exams Physics Objective questions Part 16

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Q-1. Two lenses whose powers are and respectively. The Power of Combination will be

a.

c.

d.

Q-2. In a transformer, the number of turns of primary coil and secondary coil are 5 and 4 respectively. if is applied on the primary coil, then the ration of current in primary and secondary coil is

a.

b.

c.

d.

Q-3. Two vessels of different materials are similar in size in every respect. The same quantity of ice filled in them gets melted in 20 minutes and 40 minutes respectively. The ration of thermal conductivities of the metal is

a.

b.

c.

d.

Q-4. The part of a transistor, which is heavily doped to produce a large number of majority carriers, is

a. collector

b. emitter

c. base

d. none of these

Q-5. We have a galvanometer of resistance wire. It is shunted by a 2.5 wire. The part of total current that flow through the galvanometer is given as

a.

b.

c.

d.

Q-6. The kinetic energy of a particle executing S.H.M., is 16 when it is mean position. If the amplitude of oscillation is , and the mass of the particle is then time period of the oscillation is

a.

b.

c.

d.

Q-7. A body of mass is rotating in a circular path of radius r with constant velocity. The work done in one complete revolution is

a.

b.

c.

d.

Q-8. If the surface tension of water is then the capillary rise in a tube of a diameter

a.

b.

c.

d.

Q-9. Swimming is possible by the

a. Third law of motion

b. Second law of motion

c. First law of motion

d. Newton’s law of gravitation

Q-10. In an A.C. circuit the potential different across an inductance and resistance joined in series are respectively and. The total potential different across the circuit is

a.

b.

c.

d.

Q-11. Force of attraction between the plates of a parallel plate capacitor is

a.

b.

c.

d.

Q-12. The velocity of sound is greatest in

a. vacuum

b. air

c. water

d. metal

Q-13. A force of 50 dynes is acted on a body of mass 5 gm which is at rest for an interval of 3 sec, then impulse is

a.

b.

c.

d.

Q-14. Which of the following does not change when light goes from one medium to another?

a. Speed

b. Wavelength

c. Frequency

d. intensity

Q-15. The Doppler’s effect is applicable for

a. Space waves

b. Sound waves

c. Light waves

d. Both (b) and (c)

Q-16. If the displacement of a particle executing S.H.M. is given by in metre, then the frequency and maximum velocity of the particle is

a.

b.

c.

d.

Q-17. The kinetic energy of a body of mass and momentum of 2 is

a.

b.

c.

d.

Q-18. A ray of light is incident on the surface of separation of a medium with the velocity of light at an angle and is refracted in the medium at an angle what will be the velocity of light in the medium?

a.

b.

c.

d.

Q-19. If a body of mass 3 kg is dropped from the top of a tower of height 25 metres, then its kinetic energy after 3 seconds will be

a.

b.

c.

d.

Q-20. if the balls, each of mass 0.066 kg, moving in opposite directions with speed of collide and rebound with the same speed, then the imparted to each ball due to other is

a.

b.

c.

d.

Q-21. When the amount of work done is 333 cal and change in internal energy is 167 cal, then the heat supplied is

a.

b.

c.

d.

Q-22. If an iron ball and a wooden ball of the same radius are released from a height ‘h’ in vacuum. then time taken by both of them to reach group will be

a. Roughly equal

b. Exactly equal

c. Unequal

d. Zero

Q-23. The E.M.F. of the Daniel cell is

a.

b.

c.

d.

Q-24. The speed of a wave in a medium is . If 3600 waves are passing through a point in the medium in 2 minutes, then its wavelength is

a.

b.

c.

d.

Q-25. If luminous-efficiency of a lamp is 2 lumen 1 watt and its luminous-intensity is 42 candelas then, power of the lamp is

a. 138 W

b. 76 W

c. 62 W

d. 264 W

Q-26. The specific heat of a gas in an isothermal process is

a. Negative

b. Zero

c. Infinite

d. Remains constant

Q-27. A big drop is formed by 1000 small droplets of water, then the radius of small drop is

a.

b.

c.

d.

Q-28(61). S.l unit of magnetic flux is

(a)

(b)

(c)

(d)

Q-29 (82). A parallel plate capacitor is charged to 60 Due to a radioactive source. the plate loses charge at the rate of . The magnitude of displacement current is.

a.

b.

c.

d.

Q-30. The kinetic energy of one g-molecule of a gas at normal temperature and pressure is (R=8.31 J/mole-K)

a.

b.

c.0.56

d. 3.74

Q-31. The temperature-coefficient of resistance of conductors is

a. Neutral

b. Negative

c. Positive

d. First (C) then (a)

Q-32. A black body radiates heat energy at the rate of at a temperature of The temperature of the black body, at which the rate of heat radiation in is

a.

b.

c.

d.

Q-33. Which of the following series is found in the visible region?

a. Pfund

b. Paschen

c. Lyman

d. Blamer

Q-34. When an electron is emitted from a nucleus, then effect on its neutron-proton – ration is

a. Remains same

b. Decreased

c. Increased

d. First(a) then (b)

Q-35. The half-life of a radioactive is 3.6 days. How much of 20 milligram of that radioactive will remain after 40 day?

a.

b.

c.

d.

Q-36. When a slow neutron goes sufficiently close to a nucleus then the process takes place is

a.

b.

c.

d.

Q-.37. The first operation involved in a carnot cycle is

a. Isothermal compression

b. Adiabatic expansion

c. Isothermal expansion

d. Adiabatic compression

Q-38. A body is executing simple harmonic motion with an angular frequency the velocity of the body at 20 mm displacement. When the amplitude of motion is 60 mm. is

a.

b.

c.

d.

Q-39. A tuning fork makes 250 vibrations per second in air. When the velocity of sound is 330 m/s, then wave length of the tone emitted is

a.

b.

c.

d.

Q-40. The mass of moon is if the acceleration due to gravity on the moon is the radius of the moon is

a.

b.

c.

d.

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