SCRA Selection Physics Objective Questions Part 15

Q-1. A Equation rocket is set for vertical flaring. The exhaust speed is Equation To give an initial upward acceleration of Equation the amount of gas ejected per second to supply the needed thrust will be

a. 137.5 kg/sec

b. 185.5 kg/sec

c. 127.5 kg/sec

d. 187.5 kg/sec

Q-2. A body of mass Equation and velocity Equation collides with a stationary body of mass Equation . After collision both bodies stick to each other. velocity of the bodies after collision will be

a. Equation

b. Equation

c. Equation

d. Equation

Q-3 The earth Equation revolves around the sun with an angular velocity Equation in a circular orbit of radius Equation The force exerted by sun on earth in newton is

a. Equation

b. Equation

c. Equation

d. Equation

Q-4. A bread gives a boy of mass Equation an energy of Equation . If the efficiency is Equation then height can be climbed by him using this energy, is

a. Equation

b. Equation

c. Equation

d. Equation

Q-5. At what height from the earth surface. The acceleration of gravity will be half the value of g at surface? Equation

a. Equation

b. Equation

c. Equation

d. Equation

Q-6. If the gravitational force had varied as Equation instead of Equation The potential energy of a particle at a distance Equation from the centre of the earth would be proportional to

a. Equation

b. Equation

c. Equation

d. Equation

Q-7 A satellite of mass m is circulating around the earth with constant angular velocity. if the radius of the orbit is Equation and mass of the earth is Equation The angular momentum about the centre of the earth momentum about the centre of the earth is

a. Equation

b. Equation

c. Equation

d. Equation

Q-8 A soap bubble has radius r and volume V. if the excess pressure inside the bubble is p. then PV is proportional to

a. Equation

b. Equation

c. Equation

d. Equation

Q-9. If a body of mass Equation falls from a height Equation and its total potential enery is conserved into kinetic potential energy is conserved into kinetic energy, at the point of contact of the body with the surface, then decrease in potential energy of the surface, then decrease in potential energy of the body at the contact is Equation

a. 900 J

b. 600 J

c. 400 J

d. 200 J

Q-10. A particle is projected with Equation at an angle Equation At the highest point, it explodes into three particles of equal masses. One goes vertically upwards with velocity Equation second particle goes vertically downwards. Then the velocity of the third particle will be

a. Equation

b. Equation

c. Equation

d. Equation

Q-11. A cylinder of Equation and radius Equation has moment of inertia is (about its natural axis)

a. Equation

b. Equation

c. Equation

d. Equation

Q-12 If a body starts from rest and travels 120 cm in the 8th second. Then acceleration of the body is

a. Equation

b. Equation

c. Equation

d. Equation

Q-13 A ball is falling in a lake of depth Equation creates a ddecrease Equation in its volume at the bottom. The bilk modulus of the material of the ball will be

a. Equation

Equation Equation

c. Equation

d. Equation

Q-14 Waterfalls from a height Equation The rise in temperature of water at bottom if whole of the energy remains in water, will be (specific heat of water Equation )

a. Equation

b. Equation

c. Equation

d. Equation

Q-15 A cylindrical resonance tube, open at both ends, has a fundamental frequency f in air. if half of the length is dipped vertically in water. The fundamental frequency of the air column will be

a. Equation

b. Equation

c. Equation

d. Equation

Answer;

Q-16 A wave frequency Equation has a velocity of Equation . The distance between two nearest points, if the wave is Equation out of phase, will be approximately

a. Equation

b Equation

c. Equation

d. Equation

Q-17 If the momentum of a particle is double, then its de-Broglie wavelength will become

a. Remain unchanged

b. Four times

c. Two times

d. Half times

Q-18. A wave frequency 100 Hz is send along a string towards a fixed end. When this wave travels back, after reflection, a node is formed at a distance of Equation from the fixed end of the string. The speeds of incident (and reflected) waves are

a. Equation

b. Equation

c. Equation

d. Equation

Q-19. A source of sound is travelling with a velocity Equation towards an observer and emits sounds of frequency Equation . If velocity of sounds is Equation , then apparent frequency heard by an observer is

a. Equation

b. Equation

c. Equation

d. Equation

Q-20. What is the dot product of two vectors of magnitude 3 and 5, if angle between them is Equation ?

a. Equation

b. Equation

c. Equation

d. Equation

Q-21. Dimensions of torque are

a. Equation

b. Equation

c. Equation

d. Equation

Q-22. A glass rod of Equation long is clamped at the middle. it is set into the longitudinal vibration. if the emitted sound frequency is Equation , then velocity of sound in glass will be

a. Equation

b. Equation

c. Equation

d. Equation

Q-23. If the critical angle for total internal reflection from a medium to vacuum is Equation Then velocity of light in the medium is

a. Equation

b. Equation

c. Equation

d. Equation

Q-24. The mass of the planet is Equation of the mass of the earth and its radius is half that of the radius of the earth. if a body weighs Equation on the earth, then what will be its weight on planet?

a. Equation

b. Equation

c. Equation

d. Equation

Q-25. 16 g of oxygen at Equation is mixed with Equation of nitrogen at Equation the temperature of the mixture will be

a. Equation

b. Equation

c. Equation

d. Equation

Q-26. When there is not heat change from surrounding in a system, then the process is related with

a. isobaric

b. isochoric

c. isothermal

d. adiabatic

Q-27 If the ration of specific heat of a gas at constant pressure to that at constant volume is Equation the change in internal energy of the one mole of a gas when the volume changes from Equation at constant pressure P is

a. Equation

b. Equation

c. Equation

d. PV

Q-28. The original temperature of a black body is Equation The temperature to which that black body must be raised so as to double the total radiant energy, is

a. Equation

b. Equation

c. Equation

d. Equation

Q-29. A particle of mass m and charge q is placed at rest in a uniform electric field E and then released. The kinetic energy field E and then released. The kinetic energy attained by the particle after moving a distance y is

a. Equation

b. Equation

c. Equation

d. Equation

Q-30. Four capacitors each of Equation are connected as shown in diagram the Equation voltmeter reads Equation The charge on each plate of capacitor will be..

Physics Objective Questions Part 15 Image 1

Physics Objective Questions Part 15 Image 1

Physics Objective Questions Part 15 Image 1

a. Equation

b. Equation

c. Equation

d. Equation

Q-31. Equation electric heater operates on a Equation line, then the rate at which it develops heat in watts will be

a. 1210

b. 810

c. 670

d.1310

Answer

Q-32. If the magnetic dipole is rotated through angle Equation with respect to the direct of H. Then work done will be

a. Equation

b. Equation

c. Equation

d. Equation

Q-33. If a write of resistance Equation is covered with ice and a voltage of Equation is applied across the wire then rate of melting of ice will be

a. Equation

b. Equation

c. Equation

d. none of these

Q-34. Two identical batteries, each of emf Equation volt and internal resistance Equation by passing a current through it. The maximum power that can be developed across R using these batteries is

Physics Objective Questions Part 15 Image 2

Physics Objective Questions Part 15 Image 2

Physics Objective Questions Part 15 Image 2

a. Equation

b. Equation

c. Equation

d. Equation

Q-35 The angle of minimum deviation for a thin prism with respect to air and when dipped in water will be Equation

a. Equation

b. Equation

c. Equation

d. Equation

Q-36 The velocity of an electronic in the inner most orbit of an atom is

a. highest

b. lowest

c. mean

d. Zero

Q-37. The diameter of the objective lenses of a telescope is Equation and wave length of light is Equation . The limit of resolution of this telescope is

a. Equation

b. Equation

c. Equation

d. Equation

Q-38. Light of wave length Equation falls on a sensitive plate with photoelectric work function of Equation The maximum kinetic energy of the photoelectron emitted will be

a. Equation

b. Equation

c. Equation

d. Equation

Q-39. The mass number of He is 4 and that of sulphur is 32. The radius of sulphur nucleus is larger than that of helium by a factor of

a. Equation

b. Equation

c. Equation

d. Equation

Q-40. A transistor has an Equation it has change in emitter current of 100 milliampere, then the change in the collector current is

a. Equation

b. Equation

c. Equation

d. Equation