# 2013 - JAMB Physics Past Questions and Answers - page 1

1

When a brick is taken from the earth's surface to the moon, its mass

A

remains constant

B

reduces

C

increases

D

becomes zero

**correct option:**a

2

The resultant of two forces is 50N. If the forces are perpendicular to each other and one of them makes an angle 0f 30

^{o}with the resultant, find its magnitude.A

100.0N

B

57.7N

C

43.3N

D

25.0N

3

The pair of physical quantities that are scalar only are ?

A

volume and area

B

moment and momentum

C

length and displacement

D

Impulse and time

**correct option:**a

This is because volume and the area have only magnitude but no direction

Users' Answers & Comments4

A simple pendulum of length 0.4m has a period of 2s. What is the period a similar pendulum of length 0.8m at the same place?

A

8s

B

4s

C

2\(\sqrt{2}s\)

D

\(\sqrt{2}s\)

**correct option:**c

T

= \(\sqrt{\frac{0.8 \times 2^2}{0.4}}\)

= 2\(\sqrt{2}s\)

Users' Answers & Comments_{2}= \(\sqrt{\frac{L^2 \times T_1^2}{L_1}}\)= \(\sqrt{\frac{0.8 \times 2^2}{0.4}}\)

= 2\(\sqrt{2}s\)

5

A train with an initial velocity of 20ms

^{-1}is subjected to a uniform deceleration of 2m^{-2}. The time required to bring the train to a complete halt is?A

5s

B

10s

C

20s

D

40s

6

Calculate the apparent weight loss of a man weighing 70kg in an elevator moving downwards with an acceleration of 1.5ms

[g = 10ms

^{-2}.[g = 10ms

^{-2}]A

686N

B

595N

C

581N

D

105N

7

A piece of cork floats in a liquid. What fraction of its volume will be immersed in the liquid?

[Density of the cork = 0.25 x 10

[Density of the cork = 0.25 x 10

^{3}kgm^{-3}, Density of the liquid = 1.25 x 10^{3}kgm^{-3}]A

0.8

B

0.5

C

0.2

D

0.1

8

An object is moving with a velocity of 5m

^{-1}. At what height must a similar body be situated to have a potential energy equal in value with kinetic energy of the moving body?A

25.0m

B

20.0m

C

1.3m

D

1.0m

**correct option:**c

P.E = K.E

Therefore, h = \(\frac{v^2}{2g} = \frac{5^2}{2 \times 10}\)

= 1.25

Approx 1.3 (C)

Users' Answers & CommentsTherefore, h = \(\frac{v^2}{2g} = \frac{5^2}{2 \times 10}\)

= 1.25

Approx 1.3 (C)

9

If a pump is capable of lifting 5000kg of water through a vertical height of 60m in 15 min, the power of the pump is

A

2.2.5 x 10

^{5}js^{-1}B

2.5 x 10

^{4}js^{-1}C

3.3 x 10

^{3}js^{-1}D

3.3 x 10

^{2}js^{-1}**correct option:**c

P = \(\frac{mgh}{t}\)

P = \(\frac{5000 \times 10 \times 60}{(15 \times 60)s}\)

P = 3333.3333

P = 3.3 x 10

Users' Answers & CommentsP = \(\frac{5000 \times 10 \times 60}{(15 \times 60)s}\)

P = 3333.3333

P = 3.3 x 10

^{3}js^{-1}10

The coefficient of friction between two perfectly smooth surface is

A

infinity

B

one

C

half

D

zero

**correct option:**d