Needs a Medium for Propagation

Q.

Why are sound waves called mechanical waves?

Q.

Mechanical waves need a medium for propagation.

1. False

2. True

Q.

The function of the bones in the middle ear is:

1. Protect the ear

2. Enhance the vibrations entering the ear

3. Produce sound inside the ear
4. Produce hormones essential for hearing

Q.

Choose the correct statement?

1. Only mechanical waves can be classified into transverse and longitudinal.

2. All mechanical waves are transverse

3. Sound in air is necessarily a longitudinal wave.

4. Sound can never behave as a non-mechanical wave.

Q.

Explain the auditary aspect of the human ear. [5 MARKS]

Q. Arrange the following parts of the human ear from outer to inner ear.

1. Pinna
2. Ear canal
3. Ear drum
4. Ear ossicles
5. Cochlea

Q. Which part of the human ear vibrates in response to sound waves?

Q. Statement 1: The inner part of ear has a coiled tube called "cochlea“.
Statement 2: The middle part of the ear has three small bones that amplify the vibrations.

Q. Which of the following statement(s) depict the characteristics of mechanical waves?

1. Transport both energy and matter
2. Do not need a medium to travel
3. Propagate as oscillation of particles of matter
4. Transport matter only

Q.

When sound propagates through air which of the following varies?

1. Temperature

2. Both temperature and density

3. Pressure

4. Frequency

Q. When sound enter in human ear it travel down a canal at the end of which a thin membrane is stretched tightly . what is the name of that membrane ?

Q.

A medium is able to transport a wave from one location to another location because the particles of the medium are

1. frictionless

2. isolated from one another

3. able to interact

4. very light

Q. Statement I:Astronauts cannot talk directly to each other on Moon.

StatementII: Moon has no atmosphere.

1. Only statement I is correct.
2. Only statement II is correct.
3. Both the statements are correct.
4. Both the statements are incorrect.

Q.

Describe the characteristics of wave-motion.

Q. A car driving at a constant speed of 25 $m/s$, heads straight to a mountain. The driver presses the car horn and recieves an echo 3.6 seconds later. Calculate the distance between the car and the mountain when the driver pressed the horn.

(An echo is a repeated sound that is caused by the reflection of the sound waves from the surface. Take the speed of sound in air to be 300 $m/s$. )

1. 1080 m
2. 90 m
3. 585 m
4. 495 m

Q. According to bell jar experiment, the level of sound transmitted outside the jar depends upon ___.

1. temperature
2. humidity
3. medium
4. distance

Q.

How does sound wave travel in air ?

Q. Sound is produced due to vibrations of in human beings.

1. larynx
2. vocal cords
3. pinna
4. oesophagus

Q.

Select the medium, out of those given below, in which the speed of sound is maximum at a given temperature.

1. Hydrogen gas

2. Air

3. Steel

4. Aluminum

Q. Which of the following statement(s) depict the characteristics of sound waves?

1. Transport energy only
2. Need medium to travel
3. Propagate as oscillation of particles of matter
4. Transport matter only

Q. Which part of the human ear vibrates in response to sound waves?

Q.

Choose the correct statement?

1. Only mechanical waves can be classified into transverse and longitudinal.

2. All mechanical waves are transverse

3. Sound in air is necessarily a longitudinal wave.

4. Sound can never behave as a non-mechanical wave.

Q.

During a thunderstorm, the sound of thunder is heard after lightning is seen. Why?

Q.

State the effect of pressure on the speed of sound in air.

Q. On the moon, one cannot hear sound, as there is no medium for propagation of sound wave.

1. True
2. False

Q. A big explosion on the Moon cannot be heard on the Earth. Which of the following statement is the correct explanation for this?

1. Moon has no atmosphere
2. The explosion produces high frequency sound waves which are inaudible
3. Sound wave are absorbed in the moon’s atmosphere
4. Sound waves are absorbed in the earth’s atmosphere

Q.

Sound can travel through:

1. solids only

2. liquids only

3. gases only

4. solids, liquids and gases

Q. Of the following, the velocity of sound is maximum in:

1. Air
2. Water
3. Glass
4. Vacuum

Q.

We see the lightning flash before we can hear thunder because

1. Light travels faster than sound

2. Sound travels faster than light

3. The sound of lightning is generated only after the lightning flashes.

4. Both light and sound travel with same speed

Q. Which among the following statements is true?

1. Sound moves very slowly in the outer space.
2. Intensity of sound gets reduced in the outer space.
3. Shrillness of sound gets reduced in outer space.
4. Sound cannot propagate in outer space.