IAS Physics Set - I (Read 7 times)

1. Surface temperature of the sun is of the order of
A. 5000 K    B. 7000 K    C. 6000 K    D. 12000 K

2. Two bodies A & B having masses in the ratio 1:4 have Kinetic energies in the ratio 4:1.The ratio of the linear momenta is
A. 1:4    B. 1:2    C. 1:1    D. 1:15

3. The function of base in transistor is
A. to stop the flow of electron    B. to stop the flow of current
C. to control the flow of current    D. to transmit current

4. Unidirectional property of p-n junction diode is used in
A. rectifier    B. amplifier    C. transistor    D. oscillator

5. A 238U nucleus decays by emitting an alpha-particle of speed v ms-1. The recoil speed of the residual nucleus is (in ms-1)
A. - 4v/234    B. v/4    C. - 4v/238    D. 4v/234

6. Continuous spectrum of X -rays are produced
A. when electrons move from outer to inner orbits    B. when electrons move from inner to outer orbits
C. when electrons are accelerated by moving towards the nucleus    D. none of these