Question 196:

• JAMB 1981

A solid weighs 4.8g in air, 2.8g in water and 3.2g in kerosine. The ratio of density of the solid to that of the kerosine is

A. 12
B. 3
C. 2
D. \(\frac{3}{2}\)
E. \(\frac{5}{4}\)

Question 197:

• JAMB 1981

A body of mass 6kg rests on an inclined plane. The normal reaction is R and the limiting frictional force is F as shown in the image above. if F = 30N, and g = 10ms² then the angle of inclination \( \theta \) is

A. \( 15^{\circ} \)
B. \( 30^{\circ} \)
C. \( 45^{\circ} \)
D. \( 60^{\circ} \)
E. \( 75^{\circ} \)

Question 198:

• JAMB 1981

The effect of closing the key K in the circuit shown above would be to

A. Increase the current by 0.6A
B. Reduce the current by 0.6A
C. Increase the current by 0.4A
D. Keep the current unchanged

Question 199:

• JAMB 1981

The wave motion above has a frequency

A. 0.1Hz
B. 0.2Hz
C. 5Hz
D. 10Hz
E. 100Hz

Question 200:

• JAMB 1982

The hatch door of a submarine has an area of 0.5m². The specific gravity of sea water is 1.03. Assume that g = 10ms^-1,and neglect the atmospheric pressure. The force exerted by the sea water on the hatch door at a depth of 200m is

A. 1.03 x 10⁵N
B. 1.03 x 10⁴Nm^-2
C. 1.06 x 10⁵Nm^-2
D. 2.06 x 10⁶N
E. 1.03 x 10³N