JAMB Physics Past Questions & Answers - Page 116

576.

Two forces forming a couple are separated by a distance of 25cm. If one of the forces equals 40N, what is the moment of the couple?

A.

1000 Nm

B.

500 Nm

C.

10 Nm

D.

5 Nm

E.

1.6 Nm

Correct answer is C

The moment (or torque) of a couple is calculated by multiplying the size of one of the force by the perpendicular distance between the two forces.

Given: F = 40N; d = 25cm = 0.25m

Moment = 40 x 0.25 = 10Nm.

577.

A solid weights 5.0 N in air, 4.2 N in water and 4.4 N in liquid Y. Calculate the relative density of liquid Y.

A.

0.75

B.

0.88

C.

0.95

D.

1.13

E.

1.33

Correct answer is A

No explanation has been provided for this answer.

578.

The heat from a fire in a closed room reaches someone far away in the room, mainly by

A.

reflection

B.

diffusion

C.

conduction

D.

radiation

E.

convection

Correct answer is D

No explanation has been provided for this answer.

580.

The force exerted on a charged body in an electric field depends on

I. the charge on the body
II. the electric field intensity
III. the square of the mass of the body

A.

I only

B.

II only

C.

I and II only

D.

I and III only

E.

II and III only

Correct answer is C

No explanation has been provided for this answer.