Physics Past Questions and Answers

An a.c. generator can be converted to a d.c. electric motor by replacing the

A Slip rings with a split ring and connecting a battery
B Split ring with slip rings and connecting a battery
C A.c. with d.c. source and connecting slip rings
D A.c. with d.c. source and connecting split rings

Question 1992:

A ray of light travels obliquely from a less dense medium to a denser medium. Which of the following statements is true about the light?

A The wavelength of the light increases in the second medium
B The speed of the light increases in the second medium
C The light refracts towards the normal
D There Is a change in the frequency of the light

Question 1993:

An electron of mass 9.1x 10\(^{31}\) kg is travelling at a speed of 2.0 x 10\(^6\)ms\(^{-1}\). Calculate the associate wavelength of the electron. [h = 6.6. x 10\(^{34}\) Js]

A 3.63 x10\(^{10}\) m
B 3.63 x 10\(^{-8}\) m
C 3.63 x 10\(^{-7}\) m
D 6.89 x 10\(^{-4}\) m

Question 1994:

Which of the following statements about the process of melting of a solid are true? The temperature of the solid will
I. remain steady until melting starts.
ll. keep rising until melting starts,
Ill remain steady as melting proceeds.
V, keep rising as melting proceeds.

A II and llI only
B IlI and IV only
C I, Il and Ill only
D Ll and IV only

Question 1995:

A diver steps off a diving platform that is 10m above the water. If there is no air resistance during the fall, there will be a decrease in the diver's

A Gravitational potential energy
B Total mechanical energy
C Kinetic energy
D Momentum