Physics 1988 Waec Past Questions and Answers

Question 26 :

• WAEC 1988

The velocities of light in air and glass are 3.0 x10\(^8\)ms\(^{-1}\) and 1.8 \(\times \)10\(^8\) ms\(^{-1}\) respectively. Calculate the sine of the angle of incidence that will produce an angle of refraction of 30° for a ray of light incident on glass.

A. 1.2
B. 1.0
C. 0.8
D. 0.6
E. 0.3

Question 27 :

• WAEC 1988

An object is placed 36cm from a converging lens of focal length 24cm.If a real image which is 4cm high is formed, Calculate the height of the object.

A. 2.0cm
B. 4.0cm
C. 6.0cm
D. 8.0cm
E. 10.0cm

Question 28 :

• WAEC 1988

The ability of the eye to focus objects at different distances is called

A. Power
B. Accommodation
C. Normal vision
D. Persistence of vision
E. Long sight

Question 29 :

• WAEC 1988

The change of the direction of a wave-front because of a change in the velocity of the wave in another medium is called

A. Refraction
B. Reflection
C. Diffraction
D. Interference
E. Dispersion

Question 30 :

• WAEC 1988

A source of sounds produces waves in air of wavelength1.65m. If the speed of sound in air is 330ms-1 the period of vibration in seconds is

A. 200
B. 2.0
C. 0.5
D. 0.02
E. 0.005