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.

511.

Which of the following is/are the limitations to the Rutherford's atomic models?

I. It is applicable when energy is radiated as electrons are revolving

II. It is applicable when energy is radiated in a continuous mode

III. It is applicable to an atom with only one electron in the other shell

A.

I only

B.

II only

C.

I & II only

D.

I, II & III only

Correct answer is C

Rutherford assumed that (I) energy is radiated when electrons are revolving (II) energy is radiated in a continuous mode. These are limitations of Rutherford's model

513.

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

514.

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]

515.

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