Intensity of Sound

Q.

How does increasing frequency affect amplitude?

Q. Question 8
Two children are at opposite ends of an aluminium rod. One strikes the end of the rod with a stone. Find the ratio of times taken by the sound wave in air and in aluminium to reach the second child.

Q.

What happens when amplitude increases?

Q.

When we change feeble sound to loud sound we increase its

1. Frequency

2. Amplitude

3. Velocity

4. Wavelength

Q. How do we determine the timbre of sound?

Q.

What do you mean by pure note?

Q.

The intensity of sound from a point source is $1.0\times {10}^{-6}{m}^{-2}$ at a distance of 5.0 m from the source. What will be the intensity at a distance of 25 m from the source?

1. 

2. 

3. 

4. 

Q.

Which of the following sound waves have the highest loudness?

1. 

2. 

3. 

4. 

Q. The pressure amplitude in a sound wave is tripled and frequency halved, the intensity of the sound is increased by a factor of

1. 3.25
2. 9.25
3. 1.25
4. 2.25

Q. The ratio of intensities between two coherent sound sources is 4:1. The difference of loudness in decibels between maximum and minimum intensities, when they interfere in space, is a)10 log 2 b)20 log 3 c)10 log 3 d)20 log 2

Q. A sound level $I$ is greater by $3.0103dB$ from another sound of intensity $10nWc{m}^{-2}$. The absolute value of intensity of sound level $I$ in $W{m}^{-2}$ is :

1. $2.0\times {10}^{-4}$
2. $2\times {10}^{-4}$
3. $2.0\times {10}^{-2}$
4. $2.5\times {10}^{-2}$

Q. If the loudness of a sound is reduced to 1 % then its amplitude will be

Q. The loudness of sound depends on its:

1. wavelength
2. pitch
3. frequency
4. amplitude

Q. A sound wave of wavelength 20 cm is travelling in water with speed 1600 m/s. Find its frequency.

1. 8 Hz
2. 0.8 kHz
3. 80 kHz
4. 8 kHz

Q. Loudness of a sound is measured in_________.

1. decibel
2. hertz
3. metre per second
4. metre

Q. The amount of sound passing through a unit area in 1 s is:

1. Timbre
2. Intensity
3. Frequency
4. Pitch

Q. Figure shows a tube structure in which a sound signal is sent from one end and received at the other end. The semicircular part has a radius of 20.0 cm. The frequency of the sound source can be varied electronically between 1000 and 4000 Hz. Find the frequencies at which maxima of intensity are detected. The speed of sound in air = 340 m/s.

1. 1449, 2978
2. 1500, 3000
3. 3000, 4000
4. 5000, 6000

Q. The ratio of intensities of two sound wave is 16 : 25. The ratio of their amplitudes is

1. 1 : 2
2. 5 : 4
3. 2 : 1
4. 4 : 5

Q.

Two waves of the same pitch have their amplitude in the ratio $2:3$. What will be the ratio of their loudness? What will be the ratio of their frequency?

Q. The ratio of amplitude of two waves is 3:4. What is the ratio of their:
(i) loudness? (ii) frequencies?

Q. You are asked to lower the volume of your television. How will it affect the characteristics of the sound wave?

1. Decrease in amplitude
2. Increase in amplitude
3. Increase in frequency
4. Decrease in frequency

Q.

A traveling wave is produced on a long horizontal string by vibrating and ends up and down sinusoidally. The amplitude of vibration is $1.0cm$and the displacement becomes zero$200$ times per second. The linear mass density of the string is $0.10kg{m}^{-1}$ and it is kept under a tension of$90N$.

(a) Find the speed and the wavelength of the wave.

(b) Assume that the wave moves in the position x-direction and at $t=0$, the end $x=0$ is at its positive extreme position. Write the wave equation.

(c) Find the velocity and acceleration of the particle at$x=50$$cm$ at time$t=10ms.$

Q.

The ratio of amplitude of two waves is $3:4$.What is the ratio of their loudness?

Q. The intensity of a wave is
a) Proportional to square of the frequency
b) Proportional to the velocity of wave
c) Proportional to the density of the medium
d) Proportional to the square of the distance of the source from the observer

1. a and b are true
2. Only d is true
3. a, b and c are true
4. a, b, c and d are true

Q.

The product of the time period of a wave and its frequency is

1. Infinite

2. Zero

3. More than unity but less than infinity

4. Unity

Q. What is the intensity of sound of 10 decibel?

Q. Two musical notes of the same pitch and loudness are played on a violin and a piano. The wave forms are as shown in the figures given below. Explain why the wave patterns are different.

Q. Differentiate between loudness and intensity

Q. Loudness of sound primarily depends upon

1. Frequency
2. Overtone
3. Intensity
4. Shape of the source

Q. What happens to a sound wave as it travels from air into water? (a) Its intensity increases. (b) Its wavelength decreases. (c) Its frequency increases. (d) Its frequency remains the same. (e) Its velocity decreases.