What frequency of the sound you hear coming directly from the siren?

2

(a)

A steel wire has a length of 12 m and a mass of 2.10 kg. What will be the speed of a transverse wave on this wire when a tension of 2.06\(\times \)10⁴N is applied?

2

(a)

A pipe 20 cm long is closed at one end. Which harmonic mode of the pipe is resonantly excited by a source of 1237.5 Hz? (sound velocity in air = 330ms^-1)

2

(a)

Equation of a plane progressive wave is given by y = 0.6 sin\(2\pi \left( t-\frac { x }{ 2 } \right) \) On reflection from a denser medium, its amplitude becomes 2/3 of the amplitude of  incident wave. What will be equation of reflected wave?

2

(a)

At what temperature (in ⁰C) Will be speed of sound air be 3 times its value at 0⁰ C?

2

(a)

You have learnt, that a travelling wave in one dimension is represented by a function y = f(x, t), where x and t must appear in the combination x - v t or x + vt i.e., y = f (x ± vt). Is the converse true? That is, does every function of (x - vt) or (x + vt) represent a travelling wave? Examine, if the following functions for y can possibly represent a travelling wave?
(a) (x-vt)² (b) \(log[\frac{(x+vt)}{x_{0}}]\) (c) \(\frac{1}{x+vt}\)

2

(a)

On what factors does the speed of transverse waves setup in a string depend?

2

(a)

When a vibrating tunning fork is moved speedily towards a wall, beats are heard. Why?

2

(a)

If tension of a wire is increased to four times, how is the wave speed changed?

2

(a)

What do you mean by reverberation time?

2

(a)

Why bells are made of metal and not wood?

2

(a)

How does velocity of sound in air change when temperature rises by 1⁰C?

2

(a)

Why do we not hear beats if the frequency of two sounds are widely different?

2

(a)

Define the terms 'node' and 'antinode'?

2

(a)

A light wave is reflected from the mirror. The incident and the reflected waves superimpose to form
stationary wave, but the nodes and anti-nodes are not seen. Why?

2

(a)