## Q1: Define amplitude.

Ans. It is the maximum displacement of a vibrating body on one side.

## Q2: What is called time period?

Ans. It is the time taken by a vibrating body to complete one oscillation.

## Q3: Define frequency.

Ans. It is the number of vibrations produced by a vibrating body in one second.

## Q4: What are ultrasonic waves?

Ans. It is the sound of frequencies more than 20000 hertz. We cannot hear such sounds.

Ans. Amplitude.

Ans. Frequency.

## Q7: What do you mean by the term loudness?

Ans. The sound of high amplitude is called loudness.

## Q8: Pendulum A makes 14 oscillations in five seconds and pendulum B makes 10 oscillations in three seconds. Which has a higher frequency? Express the frequency of each pendulum in hertz.

Ans.

Frequency of A = $$\frac{14}{5}$$ = 2.8 hertz

Frequency of B = $$\frac{10}{3}$$ = 3.33 hertz

Therefore,    Pendulum B has higher frequency.

## Q9: Define Hertz.

Ans. Frequency of a vibration or oscillation is measured in hertz. It is the unit of frequency.