Physics Past Questions and Answers

Which of the following is/are not affected by a magnetic field?
I. Neutrons
II. Cathode rays
III. Alpha particles

A I only
B II only
C III only
D I & III only
E I, II & III

Question 67:

An electron of charge 1.6 x 10¹⁹C is accelerated in vacuum from rest at zero volt towards a plate of 40KV. Calculate the kinetic energy of the electron.

A 4 x 10 ²⁵J
B 4 x 10²¹ J
C 6.4 x 10²⁰ J
D 6.4 x 10^-15 J
E 2.5 x 10²⁰ J

Question 68:

Which of the following is not an electromagnetic radiation?

A X-ray
B Radio waves
C Sunlight
D Sound waves
E Infra-red radiation

Question 69:

Two radioactive elements A and B have half-lives of 100 and 50 years respectively. Samples of A and B initially contain equal amounts/number of atoms. What is the ratio of the number of the remaining atoms of A to that of B after 200 years?

A 4 : 1
B 2 : 1
C 1 : 1
D 1 : 2
E 1 : 4

Question 70:

During the same interval, it is observed that a train travels the same distance as does a lorry. The two vehicles therefore have the same

A Uniform accelation
B Instateneous velocity
C Initial velocity
D Average speed
E Average velocity