Properties of Sound

Q.

In which medium sound travels faster?

1. Water vapour

2. Solid

3. Liquid

4. Gas

Q.

The speed of sound in moist air is greater than that in dry air.

1. True

2. False

Q.

Sound travels slowest in gases.

1. True
2. False

Q.

Velocity of sound in air is :

1. slower in dry air than in moist air

2. directly proportional to pressure

3. directly proportional to humidity

4. faster in dry air than in moist air

Q. Match the following physical quantities with their respective SI units.

1. $\text{Hz}$
2. $\text{m}$
3. $\text{s}$
4. $\text{dB}$

Q. A Kundts tube apparatus has a copper rod of length 1m clamped at 25 cm from one of the ends. The tube contains air in which the speed of the sound is 340 m/s. The powder collects in heaps separated by a distance of 5 cm. Find the speed of sound waves in copper.

Q.

Why is it necessary to have a material medium for sound waves to propagate?

Q.

How can astronaut talk in space without any special device.

Q. Two astronauts are floating close to each other in space. Can they talk to each other without using any special device? Give reason.

Q.

Sound requires a _________ for propagation.

Q.

An alarm bell is kept inside a vessel as shown in the below figure. A person standing close to it can distinctly hear the sound of the alarm. Now if the air inside the vessel is removed completely how will the loudness of alarm get affected for the same person?

T Air is removed through the tube Alarm clock 

Q.

We can see the lightning much before we hear the thunder. Why?

Q. Sound waves cannot travel through ______.

1. air
2. rock
3. water
4. vacuum

Q.

In humans, which organ produces sound?

1. Tongue

2. Windpipe

3. Larynx

4. Mouth

Q. The speed of sound is maximum in solids, less in liquids and least in air.

1. False
2. True

Q. The maximum displacement of the particle from its mean position is called amplitude.

1. True
2. False

Q. Properties of medium that does not affect the speed of sound are:

1. Humidity
2. Density
3. Colour
4. Lustre
5. Hardness
6. Strength
7. Volume
8. Temperature

Q. Pitch is a property of sound associated with its shrillness.

1. False
2. True

Q.

Flash and thunder are produced simultaneously. But thunder is heard a few seconds after the flash is seen. Why?

Q. We see lightning before thunder, as the speed of light is more than the speed of sound in air.

1. False
2. True

Q.

For a sound wave, the reflected wave, incident wave and the normal to the reflecting surface always lie ___.

1. in the same plane

2. in different planes

3. in planes perpendicular to each other

4. incident and reflected waves are in the same plane while normal is in a perpendicular plane

Q. Sound can travel through _______. ​

1. solids, liquids and gases​
2. liquids only
3. solids only​
4. gases only​

Q.

A string phone is placed in a vacuum chamber and Cup A is struck with a rod.​
Statement 1: Sound cannot travel from Cup A to Cup B.​

Statement 2: Vibrations cannot travel through vacuum.​