JAMB Physics Past Questions & Answers - Page 205

1,021.

The extension in a spring when 5g wt was hung from it was 0.56cm. If Hooke's law is obeyed, What is the extension caused by a load of 20g wt?

A.

1.12m

B.

2.14cm

C.

2.52cm

D.

2.80cm

E.

2.24cm

Correct answer is E

Extension & Load

Extension = K constant

\(\frac{\text{load}}{0.56cm}\) = \(\frac{X}{20g}\)

X = 2.24cm

1,022.

A liquid-in-glass thermometer should quickly register temperature changes. This is achieved by choosing a liquid that

A.

is opaque

B.

has high density

C.

has regular expansion

D.

has a high thermal conductivity

E.

can wet glass

Correct answer is D

No explanation has been provided for this answer.

1,023.

An object placed on the principle axis of a convex lens of focal length 10m produces a real image of double magnification. The image distance from the lens is

A.

30cm

B.

25cm

C.

20cm

D.

15cm

E.

10cm

Correct answer is A

\(\frac{1}{v}\) + \(\frac{1}{u}\) = \(\frac{1}{f}\)

\(\frac{1}{v}\) = +ve real image distance


where; U = +ve real object distance

f = real focus = 10

m = magnification

M = 2 = \(\frac{v}{u}\)

2u = V

\(\frac{1}{2u}\) + \(\frac{1}{u}\) = \(\frac{1}{10}\)

2u = 30

u = 15cm

v = 2u = 2 x 15

= 30cm

1,024.

The mass of a proton is approximately equal to that of

A.

an \(\alpha\)-particle

B.

a \(\beta\)-particle

C.

\(\gamma\)-ray

D.

an electron

E.

a neutron

Correct answer is E

No explanation has been provided for this answer.

1,025.

The quantity (timbre) of sound depends on

A.

amplitude

B.

frequency

C.

harmonics

D.

velocity

E.

wavelength

Correct answer is C

No explanation has been provided for this answer.