Post Utme Physics Past Questions and Answers

Question 1126:

A step-down transformer is energized by a \(220 V\) a.c. supply and supplied a current of \(10 A\) to the secondary winding. Calculate the current which flows through the primary winding if the ratio of the primary winding to secondary winding is \(10: 3\).

A. 10A
B. 3A
C. 4A
D. 5A

Question 1127:

All the following properties are characteristics of \(X\)-rays except ____________

A. They have short wavelength
B. They have no charge
C. They are electromagnetic in nature
D. They do not, affect photographic plates

Question 1128:

What particle is emitted in radioactive decay process shown above?

A. \(\beta\) particle
B. \(X\)-ray
C. \(\alpha\) particle
D. \(\gamma\)-ray

Question 1129:

Two plane mirrors are inclined at angle \(45^{\circ}\) one to another. A ray of light has incident angle \(20^{\circ}\) at the surface of the first mirror. The reflected ray is then incident on the second mirror. Calculate the angle of reflection at the second mirror.

A. \(65^{\circ}\)
B. \(45^{\circ}\)
C. \(25^{\circ}\)
D. \(20^{\circ}\)

Question 1130:

When the length of the string of a simple pendulum is its period is \(0.5 \pi\) seconds. The period when the length is increased to \(4 l\) will be ____________

A. \(0.5 \pi\) seconds
B. \(\pi\) seconds
C. 2 \(\pi\) seconds
D. \(4 \pi\) seconds