Physics questions and answers

Physics Questions and Answers

If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.

522.

During the transformation of matter from the solid to the liquid state, the heat supplied does not produce temperature increase because

A.

all the heat is used to break the bonds holding the molecules of the solid together

B.

the heat capacity has become very large as the substance melts

C.

the heat energy is quickly conducted away

D.

the heat gained is equal to the heat lost by the substance

Correct answer is A

During the transformation of the matter from the solid to the liquid state, the heat supplied does not produce a temperature increase because all the heat is used to break the bonds holding the molecules of the solid together

523.

Lamps in domestic lightings are usually in

A.

series

B.

divergent

C.

convergent

D.

parallel

Correct answer is D

Lamps in lightenings are arranged to reduce the heat losses

- resultant resistance is small for parallel arrangement which indicate low heat losses [Heat \(\alpha\) R]

524.

A train has an initial velocity of 44m/s and an acceleration of -4m/s\(^2\). Calculate its velocity after 10 seconds

A.

10m/s

B.

6m/s

C.

8m/s

D.

4m/s

Correct answer is D

V = u _ at, at u = 44m/s

44 + [-4]10

4m/s

525.

The value of T in the figure above is

A.

30N

B.

10.0N

C.

20N

D.

40N

Correct answer is D

Tsin30 + Tsin30 =40

2Tsin30 = 40

Tsin30 = 40/2 = 20

T(\(\frac{1}{2}\)) = 20

T = 20 x 2 = 40N