NCERT Solutions for Chapter: Sound, Exercise 1: Exercise

Which of these is the frequency of an infrasound?

In which of these conditions will an echo be heard?

A.R. Rehman is conducting a musical night in an open auditorium in New York. If a person who is sitting in the auditorium at a distance of $250 \mathrm{m}$ from the stage and the other one who is watching the live program on a television set sitting in front of it in Hyderabad. Then the person who hear him first is the :

If a body vibrates $50$  times in a second, then its frequency is _____.

An explosion takes place at a distance of $3200 \mathrm{m}$ away from a sound detector that detects only the sound coming from the ground as shown in the given figure.

The sound detector detects two sound signals at $0.64 \mathrm{s}$ and $0.80 \mathrm{s}$ after the explosion. Find the depth x of the soft ground. 

The velocity of sound in air, in water and in a given solid is, $330 \mathrm{m} {\mathrm{s}}^{-1}$, $1350 \mathrm{m} {\mathrm{s}}^{-1}$ and $1500 \mathrm{m} {\mathrm{s}}^{-1}$, respectively. If a vibrating tuning fork of frequency $150 \mathrm{Hz}$ is placed in each of these media, then find the distance covered by the sound in air, water and solid, respectively, at the end of $50$ vibrations.
 

Give two practical applications of reflection of sound.

An instrument produces a sound of frequency $1.5 \mathrm{kHz}$. How many vibrations are produced in the instrument in one second?