Question 641:

• JAMB 1991

A trough 12.0cm deep is filled with water of refractive index \(\frac{4}{3}\). By how much would a coin at the bottom of the trough appear to be displaced when viewed vertically from above the water surface?

A. 3.0cm
B. 6.0cm
C. 9.0cm
D. 16.0cm

Question 642:

• JAMB 1991

In a ray diagram for a thin converging lens, a ray that is not parallel to the optic axis but passes through the optic center will

A. Pass through undeviated
B. Pass through the center of curvature after refraction
C. Emerge parallel to the principal axis
D. Pass through the principal focus after refraction

Question 643:

• JAMB 1991

Which of the following correctly, describes the image of an object, 4cm from a diverging lens of focal length 12cm?

A. The image is virtual, 3cm in front of the lens
B. The image is real, 6cm behind the lens
C. The image is virtual, 6cm in front of the lens
D. The image is real, 3cm in front the lens

Question 644:

• JAMB 1991

Two tuning forks of frequency 256Hz and 260Hz are sounded close to each other. What is the frequency of the beats produced?

A. 2Hz
B. 4Hz
C. 8Hz
D. 258Hz

Question 645:

• JAMB 1991

A man hears his echo from a nearby hill 2s after he shouted. If the frequency of his voice is 260Hz and the wavelength is 1.29m, how far away is the hill?

A. 330.0m
B. 335.4m
C. 660.0m
D. 670.8m