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JAMB Physics Past Questions & Answers - Page 295

1,471.

A metal rod 800mm long is heated from 10oC to 95oC. If it expands by 1.36mm, the linear expansivity of the metal is

A.

2.0 x 102K-1

B.

2.0 x 102K-1

C.

5.0 x 10-3K-1

D.

2.0 x 10-5K-1

Correct answer is D

a = 1.36800×(9510)

= 2.0 x 10-5K-1

1,472.

The thermometric properties of the thermocouple is that is

A.

e.m.f. changes with temperature

B.

resistance changes with temperature

C.

volume changes with temperature

D.

pressure changes with resistance

Correct answer is A

No explanation has been provided for this answer.

1,473.

An object of mass 400g and density 600kgm-3 is suspended with a sting so that half of it is immersed in paraffin of density 900kgm-3. The tension in the string is

A.

1.0N

B.

3.0N

C.

4.0N

D.

5.0N

Correct answer is B

volume of object = 400×102600

= 0.00067m3

volume of paraffin displaced = 12 x 0.00067

= 0.00034m3

mass of paraffin = 900 x 34 x 10-5

= 0.3kg

weight of paraffin = 0.3 x 10

= 3N = upthrust = tension in the string

1,475.

A plane inclined at angle θ has a velocity ratio of 10 : 1. The inclination of the plane to the horizontal is given by

A.

tanθ = 110

B.

cotθ = 110

C.

cosθ = 110

D.

sinθ = 110

Correct answer is D

V.R = 1sinθ

= 10

sin = 110