JAMB Physics Past Questions & Answers - Page 189

941.

The heights of the mercury thread in a mercury-in-glass thermometer when in melting ice and then in steam are 3cm and 18cm respectively. At a temperature of 60oC the height would be

A.

7.5cm

B.

9cm

C.

10.8cm

D.

12cm

E.

12.6cm

Correct answer is D

18cm .... 100oC

x .... 60oC

3cm .... 0oC

\(\frac{x - 3}{18 - 3}\) = \(\frac{60 - 0}{100 - 0}\)

= 12cm

942.

If the wavelength of a wave traveling with a velocity of 360ms-1 is 60m, the period of the wave is

A.

6s

B.

3.6s

C.

0.17s

D.

0.61s

E.

3s

Correct answer is C

V = \(\alpha\)F and F = \(\frac{1}{T}\)

v = \(\frac{\pi}{T}\)

T = \(\frac{60}{360}\)

T = 0.17s

943.

When the vapour of a substance is in equilibrium with its own liquid, it is said to be

A.

gaseous

B.

unsaturated

C.

liquefied

D.

diffused

E.

saturated

Correct answer is E

No explanation has been provided for this answer.

944.

In what range of temperature is the expansion of water anomalous?

A.

+208oC to +212oC

B.

-80oC + -76oC

C.

-4oC to 0oC

D.

+96oC to +100oC

E.

0oC to +4oC

Correct answer is E

No explanation has been provided for this answer.

945.

If in a simple pendulum experiment the length of the inextensible string is increased by a factor of four, its period is increased by a factor of

A.

4

B.

\(\frac{\pi}{2}\)

C.

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

D.

2\(\pi\)

E.

2

Correct answer is E

In simple pendulum, T = 2\(\pi\)\(\sqrt\frac{L}{g}\)

\(\frac{T_2}{T_1}\) = \(\sqrt\frac{L_1}{L_2}\) but, L2 = 4L1

\(\frac{T_2}{T_1}\) = \(\sqrt\frac{L_1}{4L_1}\)


T2 = 4T1