Through what type of media, can (i) the transverse waves and (ii) the longitudinal waves be transmitted? Give reason.

2

(a)

Give some examples of waves which are combination of both transverse and longitudinal wave motion.

2

(a)

The sound of school bell is heard by all students in the school. Describe how is sound produced by the bell and how it propagates through air to reach you in the school playground.

2

(a)

Define wave number.

2

(a)

Distinguish between particle velocity and wave velocity?

2

(a)

On what factor does the frequency of a wave depend?

2

(a)

Why is sound wave called a longitudinal wave?

2

(a)

A person has a hearing range from 20 Hz to 20 kHz. What are the typical wavelengths of sound waves in air corresponding to these two frequencies? Take the speed of sound in air as 344 m s^–1.

2

(a)

Does sound follow the same laws of reflection as light does? Explain.

2

(a)

A sound wave travels at a speed of 339 m s^–1. If its wavelength is 1.5 cm, what is the frequency of the wave? Will it be audible?

2

(a)

What is reverberation? How can it be reduced?

2

(a)

It is observed that some animals get disturbed before earthquake. How?

2

(a)

What is hearing aid? Briefly describe its working principle.

2

(a)

What is ultra sound? State the special properties of ultrasound that make it useful to us.

2

(a)

What are ultrasonic? Give two applications of ultrasonic waves.

2

(a)