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.

4,031.

A turning fork of frequency 340Hz is vibrated just above a cylindrical tube of height 1.2m. If water is slowly poured into the tube, at what maximum height will resonance occur.
[speed of sound in air = 340ms-1]

A.

0.95m

B.

0.60m

C.

0.50m

D.

0.45m

Correct answer is D

In vibration in a closed pipe/tube, the first resonance occurs at a position L = V/4f,
when reading from the top of the tube,

L1 =_340
4 x 340

= 0.25m
L2 = 3V/4f
L2 = 3 x 340
4 x 340

= 0.75m
L3 = 5V/4f
L3 = 5 x 340
4 x 340

= 1.25m
However, the effective length of the tube is 1.2m. Thus reading from below, the first position of resonance will be 1.20 - 0.75m = 0.45m

4,032.
4,033.

A satellite is in a parking orbit if its period is

A.

less than the period of the earth

B.

more than the period of the earth

C.

equal to the period of the earth

D.

the square of the period of the earth

Correct answer is C

A satellite is said to be in a parking orbit if its period is exactly equal to the period of the earth as it turns its own orbit;. which is about 24hrs

4,034.

The stylus of a phonograph record exerts a force of 7.7 x 10-2N on a groove of radius 10-5m. Compute the pressure exerted by the stylus on the groove

A.

2.45 x 108 Nm-2

B.

3.45 x 108 Nm-2

C.

4.90 x 108 Nm-2

D.

2.42 x 108 Nm-2

Correct answer is A

No explanation has been provided for this answer.

4,035.

Water does not drop through an open umbrella of silk materials unless the inside of the umbrella is touched. This is due to

A.

capilarity

B.

osmotic pressure

C.

viscosity

D.

surface tension

Correct answer is D

Surface tension - The tendency of a liquid surface to behave as an elastic skin