JAMB Physics Past Questions & Answers - Page 231

1,151.

In order to find the depth of the sea, a ship sends out a sound wave and receives an echo after one second. If the velocity of sound in water is 1500ms-1, what is the depth of the sea?

A.

0.75km

B.

1.50km

C.

2.20km

D.

3.00km

E.

3.75km

Correct answer is A

Echo time = 1 \(\div\) 2 = 0.5sec

depth = velocity x time

= 1500 x 0.5

= 750m = 0.75km

1,152.

Which of the following phenomena CANNOT be explained by the molecular theory of matter?

A.

Expansion

B.

Conduction

C.

Convection

D.

Radiation

E.

Evaporation

Correct answer is D

No explanation has been provided for this answer.

1,153.

Which of the following statements are NOT correct?

A.

boiling occurs when the saturated vapour pressure of the liquid involved equals the external pressure

B.

both the boiling point and the saturated vapour pressure of a given liquid depends on the external pressure

C.

the saturated vapour presssure rises with increase in temperature

D.

the saturated vapour pressure is independent of the volume available for the vapour

E.

it is possible to boil water at a lower temperature than 100oC at high altitude

Correct answer is D

The saturated vapour pressure is dependent on the temperature of the liquid and not on the volume.

1,154.

A good calorimeter should be of

A.

low specific heat capacity and low heat conductivity

B.

low specific heat capacity and high heat conductivity

C.

high specific heat capacity and low heat conductivity

D.

high specific heat capacity and low heat conductivity

E.

dull surface and low heat conductivity

Correct answer is B

No explanation has been provided for this answer.

1,155.

Two thermo flasks of volume Vx and Vy are filled with liquid water at an initial temperature of 0oC. After sometime the temperature were found to be 9x, 9y, respectively. Given that \(\frac{Vx}{Vy}\) = 2 and \(\frac{\theta x}{\theta y}\) = \(\frac{1}{2}\) the ratio of the heat flow into the flask is

A.

\(\frac{1}{4}\)

B.

\(\frac{1}{2}\)

C.

4

D.

1

E.

2

Correct answer is D

Heat = mc\(\theta\)

Hx = Dx x Vx x Cx x \(\theta\)x

Hy = Dy x Vy x Cy x \(\theta\)y

\(\frac{H_x}{H_y}\) = \(\frac{D_x \times V_x \times C_x \times \theta_x}{D_x \times V_x \times C_x \times \theta_x}\)

= 2 x \(\frac{1}{2}\)

= 1