# 2004 - WAEC Physics Past Questions and Answers - page 1

1

The molecular structure of a liquid is such that

A

the molecules have unlimited freedom of movement

B

molecular movement is restricted to vibration only

C

intermolecular collisions take place

D

all molecules moves move with the same speed

**correct option:**c

2

Which of the following statements about the mass and the weight of a body is not correct? its

A

mass is a scalar quantity

B

weight is a function of the gravitational pull on it

C

mass on earth and on the moon is the same

D

weigh at the equatior and at the poles is the same

**correct option:**d

3

An object weighs 60.0N in air, 48.2N in a certain liquid X, and 44.9N in water, Calculate the relative density of X

A

3.300

B

1.279

C

0.932

D

0.782

**correct option:**d

R.d = Wt in Air-Wt in Air-Wt in water

= \(\frac{60.0 - 48.2}{60.0 - 44.9}\)

= 0.782

Users' Answers & Comments= \(\frac{60.0 - 48.2}{60.0 - 44.9}\)

= 0.782

4

Calculate the change in volume when 90g of ice is completely melted. [density of water = 1g cm

^{-3}, density of ice = 0.9cm^{-3}]A

0.00cm

^{3}B

9.00cm

^{3}C

10.00cm

^{3}D

90.00cm

^{3}**correct option:**c

\(\Delta\)y = V

= \(\frac{90}{0.9} - \frac{90}{1} = 10cm^3\)

Users' Answers & Comments_{ice}- V_{water}= \(\frac{90}{0.9} - \frac{90}{1} = 10cm^3\)

5

The diagram above represent displacement D, versus time, t graph of a progressive wave. Deduce the frequency of the wave

A

20 Hz

B

10 Hz

C

5 Hz

D

4 Hz

**correct option:**b

6

Which of the following concept is not an evidence of the particle nature of matter?

A

diffusion

B

brownian motion

C

diffraction

D

crystallization

**correct option:**d

7

A diver is 5.2m below the surface of water of density 1000Kgm

^{-3}. If the atmospheric pressure is 1.02 x 10^{5}pa. Calculate the pressure on the diver [g = 10ms^{-2}]A

6.20 x 10

^{4}paB

1.02 x 10

^{5}paC

1.54 x 10

^{5}paD

5.20 x 10

^{5}pa**correct option:**c

P = hpg + A.P

= 5.2 x 1000 x 10 + 1.02 x 10

= 1.54 x 10

Users' Answers & Comments= 5.2 x 1000 x 10 + 1.02 x 10

^{5}= 1.54 x 10

^{5}8

A steel needle floating on water, sinks when kerosine is added to the water. This is because the kerosine

A

increased the surface tension of the water

B

reduces the density of the water

C

reduces the surface tension of the water

D

reduces the upthrust on the needle

**correct option:**c

9

On which of the following factor does the viscosity of a liquid depend? i. Nature of the liquid. ii. Temperature of the liquid. iii. Area of the liquid surface

A

i and ii only

B

ii and iii only

C

i and iii only

D

i, ii and iii

**correct option:**d

10

An elastic string of force constant 200N m

^{-1}is stretched through 0.8m within its elastic limit. Calculate the energy stored in the stringA

64.0J

B

80.0J

C

128.0J

D

160.0J

**correct option:**a

E = \(\frac{1}{2}Ke^2\)

= \(\frac{1}{2} \times 200(0.8)^2 = 64J\)

Users' Answers & Comments= \(\frac{1}{2} \times 200(0.8)^2 = 64J\)