Post Utme Physics Past Questions and Answers

Question 1126:

A step-down transformer is energized by a $220V$ a.c. supply and supplied a current of $10A$ 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 $4l$ will be ____________

A. $0.5\pi$ seconds
B. $\pi$ seconds
C. 2 $\pi$ seconds
D. $4\pi$ seconds