Light, Heat, Thermodynamics, Wave Motion, Sound, Optics & Oscillations - Category Wise Question And Answer Practice Test With Solutions

Question : 21

The velocity of sound in any gas depends upon

a) intensity of sound waves only

b) wavelength of sound only

c) density and elasticity of gas

d) amplitude and frequency of sound

Question : 22 [IAS (Pre) 2001]

When water is heated from 0ºC to 10ºC. It’s volume

a) Decreases

b) Does not change

c) Increases

d) First decreases and then increases

Question : 23 [PCS (Pre) 2005]

The body temperature of a healthy man is

a) 37° Fahrenheit

b) 98.4° Celsius

c) 37° Celsius

d) 98.4° Kelvin

Question : 24

Consider telecommunication through optical fibres. Which of the following statement is not true?

a) Optical fibres are subject to electromagnetic interference from outside

b) Optical fibres can be of graded refractive index

c) Optical fibres have extremely low transmission loss

d) Optical fibres may have homogeneous core with a suitable cladding

Question : 25 [UPPCS (Mains) 2002]

Consider the following statements.

1. The heart vibrates at infrasonic.
2. The speed of sound is more in gas than in liquid and solid.
3. Mach number is used to describe the speed of sound.
4. Ultrasonic sound has frequency more than 20,000 Hz.

a) 2, 3 and 4 are correct

b) 1, 3 and 4 are correct

c) 1, 2 and 3 are correct

d) 1, 2 and 4 are correct