Jamb Physics 1993 Past Questions and Answers

Question 21:

• JAMB 1993

Which of the following may be used to explain a mirage? i. layers of air near the road surface have varying refractive indices in hot weather. ii. road surfaces sometimes become good reflectors in hot weathers. iii. light from the sky can be reflected upwards after coming close to the road surface.

A. Ii only
B. Ii and iii only
C. I and iii only
D. I, ii, and iii only

Question 22:

• JAMB 1993

A beam of light is incident from air to water at an angle of 30^oC. Find the angle of refraction if the refractive index of water is \(\frac{4}{3}\)

A. 15^oC
B. 18^oC
C. 22^oC
D. 24^oC

Question 23:

• JAMB 1993

The property of the eye known as its power of accommodation is controlled by the

A. Pupil
B. Virteous humour
C. Iris
D. Ciliary muscles

Question 24:

• JAMB 1993

Which of the following correctly explain(s) why a green leaf appears green in bright day light? i. it absorbs only the green component of sunlight. ii. it absorbs all colour of sunlight except green. iii. it reflects only the green component of sunlight.

A. I only
B. Ii only
C. I and iii only
D. Ii and iii only

Question 25:

• JAMB 1993

Which of the following correctly explains why soft iron is proffered to steel in electromagnets? i. soft iron is more readily magnetized than steel. ii. soft iron is more readily demagnetized than steel. iii. soft iron retains magnetism more than steel.

A. I only
B. Ii and iii only
C. I and ii only
D. I, ii, and iii.