Question 171:

• JAMB 1981

The resistance of a 240V, 60 watt electric filament bulb is

A. 0.25\(\Omega\)
B. 480\(\Omega\)
C. 60\(\Omega\)
D. 240\(\Omega\)
E. 960\(\Omega\)

Question 172:

• JAMB 1981

An aircraft travelled from calabar to kano as follows: it flew first to ilorin convering a distance of 300km, 30^o west of North, and then flew 400km, 60^o East of North to kano. What is the resultant displacement?

A. 567km
B. 410km
C. 594km
D. 500km
E. 600km

Question 173:

• JAMB 1981

All of the following frequencies are overtones of 320 Hz EXCEPT

A. 960Hz
B. 640Hz
C. 520Hz
D. 1280Hz
E. 1600Hz

Question 174:

• JAMB 1981

The driver in a motor car, of which the total mass is 800kg and which is traveling at 20ms^-1, suddenly observes a stationary dog in his path 50m ahead. If the car brakes can exert a force of 2000N, what will most likely happen?

A. The car will be able to stop immediately the driver notices the dog
B. The car will stop 3pm after hitting the dog
C. The car will stop 20m in front of the dog
D. The driver will quickly reverse the car
E. The car will stop 5m beyound the dog

Question 175:

• JAMB 1981

The absolute refractive indices of glass and water are \(\frac{3}{2}\) and \(\frac{4}{3}\) respectively. The refractive index at the interface when a ray travels from water to glass is

A. \(\frac{1}{2}\)
B. \(\frac{8}{9}\)
C. \(\frac{9}{8}\)
D. \(\frac{17}{12}\)
E. 2