Question 206:

• JAMB 1982

The echo of a sounder from the bottom of an ocean is heard 2.5 seconds later. If the speed of sound in water is 1,400ms^-1, the depth of the ocean is

A. 1,750m
B. 3,500m
C. 1,400m
D. 2,800m
E. 2,100m

Question 207:

• JAMB 1982

An electric iron is rated at 1000watts, 250v. The corresponding maximum resistance and accompanying current is

A. 62.5A, 4.0\(\Omega\)
B. 16.0A, 62.5\(\Omega\)
C. 62.5A, 16.0\(\Omega\)
D. 4.0A, 62.5\(\Omega\)
E. 4.0A, 250\(\Omega\)

Question 208:

• JAMB 1982

The force responsible for holding the moon in its orbit around the earth against the gravitational pull of the earth is

A. Centrifugal
B. Rotational
C. Reaction
D. Centripetal
E. Tractional

Question 209:

• JAMB 1982

A mango fruit drops from a branch 10m above the ground, just before hitting the ground its velocity is (g = 10ms^-2)

A. 10√2ms^-1
B. 10ms^-1
C. 100ms^-1
D. 5√2ms^-1
E. 200ms^-1

Question 210:

• JAMB 1982

Which of the following machines does NOT apply the lever principle?

A. Claw hammer
B. Wheel barrow
C. Single moving pulley
D. Sugartongs
E. Nutcrackers