Time Period and Frequency

Q. The amount of sound energy passing per unit area in unit time is called _______ of sound.

1. frequency
2. wavelength
3. intensity
4. tone

Q. A wave produces 40 crests and 40 troughs in 0.2 seconds. Calculate the frequency of the wave.

1. $300Hz$
   
2. $400Hz$
   
3. $200Hz$
   
4. $500Hz$
   

Q.

Question 5
When we change feeble sound to loud sound we increase its

(a) frequency
(b) amplitude
(c) velocity
(d) wavelength

Q.

A longitudinal wave travels through a coiled spring at a speed of $4m{s}^{-1}$. The distance between two consecutive compression is $20cm$. Find the frequency of the wave?

1. 15 hertz

2. 20 hertz

3. 25 hertz

4. 30 hertz

Q. Label the parts of the longitudinal wave given below.

1. Compression
2. Wavelength
3. Rarefaction

Q.

The pitch of the sound is determined by:

1. Speed of sound

2. Frequency

3. Intensity

4. Amplitude

Q.

A person is standing 1 km away from a source of sound. If the velocity of sound in the medium is 340 m/s, then calculate the number of oscillations (approximately) that the sound wave makes before it reaches that person. The frequency of the sound is 500 Hz.

1. 1450

2. 1417

3. 1470

4. 340

Q.

A wave source produces $20$ crests and $20$ troughs in $0.2sec$. Find the frequency of the wave.

1. $200Hz$

2. $500Hz$

3. $100Hz$

4. $300Hz$

Q.

A sound wave having a wavelength of 20 cm is travelling in water. If the velocity of sound in water is $1600m{s}^{-1}$, then find the frequency of the sound wave.

1. 9000 Hz

2. 8000 Hz

3. 7000 Hz

4. 1600 Hz

Q. Sound of single frequency is known as a/an

1. tone
2. note
3. overtone

Q.

The unit of the quantity on which pitch of the sound depends:

1. hertz

2. second

3. metre/second

4. metre

Q. The time period of sound is increased by 4 times. Find the ratio of the new speed to the old speed.

1. 8
2. 2
3. 4
4. 1

Q.

The frequency of a tuning fork that vibrates 5000 times in 5 s is __________.

1. 750 Hz

2. 1250 Hz

3. 1000 Hz

4. 1500 Hz

Q. A wave source produces 20 crests and 20 troughs in 0.2 seconds. Find the frequency of the wave.

1. $300Hz$
2. $200Hz$
3. $500Hz$
4. $100Hz$

Q. A wave produces 40 crests and 40 troughs in 0.2 seconds. Calculate the frequency of the wave.

1. $200Hz$
2. $300Hz$
3. $400Hz$
4. $500Hz$