Crest and Trough

Q. You recognize your friend by hearing his voice on a telephone. Explain.

Q. Quality is the characteristic of sound which enables us to distinguish two sounds of same frequency and amplitude.

1. True
2. False

Q.

The SI unit of frequency.

Q. Sound consisting of a single frequency is called a .

1. note
2. tone
3. pitch

Q. is the most important factor which helps in recognising a person solely by his voice.

1. Loudness
2. Pitch
3. Quality

Q. The given plot represents the change in density of the particles as sound travels through a medium. Which of the following statements is/are correct with respect to corresponding pressure-distance graph?

1. Region A will be represented as a crest.
2. Region B will be represented as a trough.
3. Region A will be represented as a trough.
4. ​​​​​​Region B will be represented as a crest.