Embibe Experts Solutions for Chapter: Sound Waves, Exercise 1: Exercise 1

The displacement sound wave in a medium is given by the equation $Y=A\cos (ax+bt)$ where $A, a$ and $b$ are positive constants. The wave is reflected by a denser obstacle situated at $x=0.$ The intensity of the reflected wave is $0.64$ times that of the incident wave. Tick the statement among the following that is incorrect.

A sound wave is travelling in a medium. If equation of displacement wave in the medium is given by $y=2\cos \left(2\pi x-100\pi t+\frac{\pi }{2}\right)$ then equation of pressure waves will be ($B\to$ Bulk modulus of medium)

A source of sound is in the shape of a long narrow cylinder radiating sound waves normal to the axis of the cylinder. Two points $P$ and $Q$ are at perpendicular distances of $9 \mathrm{m}$ and $25 \mathrm{m}$  from the axis. The ratio of the amplitudes of the waves at $P$ and $Q$ is:-

Dependence of disturbances due to two waves on time is shown in the figure. The ratio of their intensities $\frac{I_1}{I_2}$ will be:-

At the same temperature and pressure the densities of two diatomic gases are $d_1$ and $d_2$. The ratio of velocities of sound in these gases will be

At room temperature $\left(27°\mathrm{C}\right),$ the velocity of sound in air is $330 \mathrm{m} {\mathrm{s}}^{-1}.$ The increase in velocity of sound when temperature is increased by $1°\mathrm{C}$ is

Assuming the temperature to be constant, as we go up in the atmosphere, the velocity of sound

Two vibrating strings ' $A$ ' and ' $B$ ' produce beats of frequency $8 \mathrm{Hz}$. The beat frequency is found to reduce to $4 \mathrm{Hz}$ if the tension in the string $\text{'}A\text{'}$ is slightly reduced. If the original frequency of $A$ is $320 \mathrm{Hz}$, then the frequency of $B$ ' is