JAMB Physics Past Questions & Answers - Page 165

821.

Calculate the gravitation force of attraction between two planets of 1024kg and 1027kg separated by a distance of 1020meters.

A.

6.67N

B.

6.56N

C.

7.5N

D.

8.6N

Correct answer is A

F = (Gm1m2) ÷ r2

M1 = 1024Kg, M2 = 1027Kg , r = 102

(Note: the gravitational constant of G = \(6.67 × 10^{ 7ndash; 11}\) \( Nm^2/Kg^2 \)

F = \( (6.67 × 10^{– 11 + 24 + 27)} 10^40 = 6.67 × (10^40 ÷ 10^40)

= 6.67N

f = 6.67N

822.

If an object is placed at a height of tem above the ground at a stationary point. It posses what types of energy?

A.

Mechanical energy

B.

Stationary energy

C.

Potential energy

D.

Vibrational energy

Correct answer is C

Energy due to position T is potential energy (P.E)

Energy due to motion is kinetic energy (K.E)

823.

In which of the following device is the expansion of solid not required?

I. Simple pendulum
II. Fire alarms
III. Thermostat
IV. Bimetallic thermometer

A.

III only

B.

II & III only

C.

I only

D.

II, III & IV only

Correct answer is C

Simple pendulum does not depend on thermal expansion

Five alarms, Thermostat and Bimetallic thermometer are application of thermal expansion of solid

There is an explanation video available below.

824.

Which of the following is not luminous object?

A.

The sun

B.

The moon

C.

light candle

D.

Star

Correct answer is B

Sun are self luminous source
Moon is a non – luminous

There is an explanation video available below.

825.

A motor boy of a driver saw what seems to appear to be a pool of water a head of him, while his driver drives a new truck on a sunny day. Which of the following explains his observation?

A.

He saw a flying objects

B.

He must be thinking of water and food

C.

He was seeing the shadow of the car

D.

The sun ray from the sky were passing from a hot air (layer) to cold layer

Correct answer is D

The appearance of pool of water on road surfaces is called MIRAGE

His observation show that light from the sun ray refracted through a layer of hot air(layer) which is closed to the ground, passes from a hot air layer to the cold layer