Question 876:

• JAMB 1997

A boy on looking into a mirror observed that his face appeared to have grown bigger. The boy must have been looking at a

A. Convex mirror with his face at the focus
B. Concave mirror with his face between the focus and the mirror
C. Concave mirror with his face at the focus
D. Convex mirror with his face between the focus and the mirror

Question 877:

• JAMB 1997

Light of velocity 3 x 10⁸ms^-1 is incident on a material of reflective of index n. If the velocity of light is reduced to 2.4 x 10⁸ms^-1 in the material, what is n?

A. 2.33
B. 2.25
C. 1.33
D. 1.25

Question 878:

• JAMB 1997

The electromagnetic waves that are sensitive to temperature changes are

A. X-rays
B. Gamma-rays
C. Ultra-violet rays
D. Infra-red rays

Question 879:

• JAMB 1997

Three electric cells each of e.m.f 1.5V and internal resistance of 1.0\(\Omega\) are connected in parallel across an external resistance of \(\frac{2}{3}\)\(\Omega\). Calculate the value of the current in the resistor

A. 0.5 A
B. 0.9A
C. 1.5A
D. 4.5A

Question 880:

• JAMB 1997

A galvanometer of internal resistance 50\(\Omega\) has a full scale deflection for a current of 5mA. What is the resistance required to covert it to a voltmeter with full scale deflection of 10V?

A. 1750\(\Omega\)
B. 1950\(\Omega\)
C. 2000\(\Omega\)
D. 2500\(\Omega\)