Sound Waves

Q. Sound requires a medium to travel .

1. the particles of the medium
2. the medium

Q.

Do Sound waves always travel in a straight line ?

Q. The waves that need a material medium for propagation is called ________ waves .

1. 2 s
2. 3 s
3. 4 s
4. 1 s

Q.

What is the difference between free and forced vibration?

Q.

A wire stretched between two fixed supports, is plucked exactly in the middle and then released. It executes___.(neglect the resistance of the medium)

1. damped vibration

2. natural vibration

3. forced vibration
4. resonant vibration

Q.

Consider the following statements:

Statement 1: No sound can be heard on the surface of the Moon.
Statement 2: Temperature of the surface of the Moon is very high and hence sound waves cannot be produced.

Choose the correct options.

1. Only Statement 1 is correct

2. Only Statement 2 is correct​

3. Both the Statements are correct

4. Both the Statements are incorrect

Q.

A rubber band tied between 2 ends is stretched and then left, a sound is heard due to :

Q.

_____ waves consist of compressions and rarefactions

Q. Sound wave are not polarized because:

1. Their speed is less
2. A medium is needed for their propagation
3. These are longitudinal
4. Their speed depends on temperature

Q.

Before playing the orchestra in a musical concert, a sitarist tries to adjust the tension and pluck the string suitably. By doing so, he is varying the:

1. Amplitude of sound

2. Frequency of the sitar string with the frequency of other musical instruments.

3. Intensity of sound

4. Loudness of sound

Q.

Sound can travel easily through vacuum

1. True
2. False

Q.

When sound waves travel from a rarer gaseous medium to a denser gaseous medium, its speed __.

1. decreases

2. remain constant

3. increases

4. may increase or decrease

Q. Choose the correct statement(s) about sound in air from the options below.

1. Longitudinal wave
2. Mechanical wave
3. Electromagnetic Wave
4. Transverse wave

Q.

What is the repeated reflection resulting in the persistence of sound in a large hall called?

Q. Sound travels faster in rarer medium but Why density of air decreases with increasing humidity or moisture and is said that density of humid air is 5\8 th times density of normal air? Should not density of air increase with more water vapour ?

Q.

Which of the factors varies when sound propagates through air molecules?

1. Frequency

2. Pressure

3. Density

4. Temperature

Q.

Sound cannot travel in

1. Intensity of sound gets reduced in the outer space

2. Sound cannot propagate in vacuum

3. Sound moves very slowly in the outer space

4. None of these

Q.

18. In ________ layer of atmosphere TV waves do not get reflected. Hence, artificial satellites are used for television transmission.

Q.

Can sound waves travel in a vacuum?

Q.

There are two boxes A & B. Cell phones are kept in both the boxes, all air is sucked from box A and then closed by a device. While box B is simply closed by a device without sucking air from it. A call is made simultaneously from both the phones, but sound comes only from box B. This is because:

Statement 1: In box A, there are air particles to vibrate and box B is a vacuum.
Statement 2: Sound needs a medium for propagation.

1. Statement 1 is true and statement 2 is the correct explanation of statement 1

2. Statement 1 is true but statement 2 is not the correct explanation of statement 1

3. Statement 1 is true but statement 2 is false

4. Statement 1 is false but statement 2 is true

Q. A disturbance creates oscillations perpendicular (at right angles) to the propagation of the wave. Is it sound wave or light wave? [1 Mark]

Q.

Match the statements of column A and column B:

Column A	Column B
A) Velocity of sound is constant	p) Phase change of $\mathrm{\pi }$ radian
B) Reverberation	q) Wave motion
C) Reflection of sound wave in an open tube	r) Homogeneous medium
D) Transverse wave cause	s) Change in shape of medium
E) Transfer of energy	t) Sound- absorbing materials

1. A→ q; B→ r; C→ t; D→ p; E→ s

2. A→ s; B→ p; C→ s; D→ r; E→ s

3. A→ r; B→ t; C→ p; D→ s; E→ q

4. A→ r; B→ t; C→ s; D→ p; E→ q

Q.

In a microphone, _______________ energy is converted into ____________ energy.

Q. Fill in the blank.

1. the source
2. the particles of the medium
3. the disturbance
4. the medium

Q. Plates move towards each other in :

1. divergent boundary
2. tensional boundary
3. conservative boundary
4. compression boundary

Q.

When a star reaches a certain point in its life, it may explode and become a supernova. When it does this, it gives out energy in the form of waves which travel to the earth through space. Which of these could not be received from the star?

1. Radio waves

2. Sound waves

3. Gamma radiations

4. Visible radiations

Q.

Give one word for the energy produced due to vibrations of an object.

Q.

If a tunning fork is vibrating freely, then its vibration will be:

1. forced

2. damped

3. resonant

4. natural

Q. Find the minimum and maximum wavelengths of sound in water that is in the audible range for an average human ear. Speed of sound in water is 1450 m/s.

Q.

What is the range of hearing of human beings? Around which frequency of sound are our ears most sensitive?