The speed of sound in a medium is \(v\). If the density of the medium is doubled at constant pressure, what will be the new speed of sound?
1. | \(\sqrt{2} v \) | 2. | \(v \) |
3. | \(\frac{v}{\sqrt{2}} \) | 4. | \(2v\) |
A transverse wave moves from a medium \(A\) to a medium \(B\). In medium \(A\), the velocity of the transverse wave is \(500~\text{ms}^{-1}\) and the wavelength is \(5~\text{m}\). The frequency and the wavelength of the wave in medium \(B\) when its velocity is \(600~\text{ms}^{-1}\), respectively are:
1. | \(120~\text{Hz}\) and \(5~\text{m}\) | 2. | \(100~\text{Hz}\) and \(5~\text{m}\) |
3. | \(120~\text{Hz}\) and \(5~\text{m}\) | 4. | \(100~\text{Hz}\) and \(6~\text{m}\) |
Sound waves travel at \(350\) m/s through warm air and at \(3500\) m/s through brass. The wavelength of a \(700\) Hz acoustic wave as it enters brass from warm air:
1. | increase by a factor of \(20\) |
2. | increase by a factor of \(10\) |
3. | decrease by a factor of \(20\) |
4. | decrease by a factor of \(10\) |
A sound wave is passed through a chamber. If the r.m.s. speed of molecules in a gas is v1 and the speed of sound is v2 in the gas, then:
1. | v1 = v2 | 2. | v1 > v2 |
3. | v1 < v2 | 4. | v1 ≤ v2 |
A person standing between two parallel hills fires a gun and hears the first echo after sec and the second echo after sec. The distance between the two hills is: [Given: Speed of sound = v]
A bat emits an ultrasonic sound of frequency 1000 kHz in the air. If the sound meets a water surface, what is the wavelength of the reflected sound? (The speed of sound in air is 340 m/sec and in water is 1486 m/sec)
1. \(3.4 \times 10^{-4}~\text{m}\)
2. \(1 . 49 \times 10^{- 3} ~ \text{m}\)
3. \(2 . 34 \times 10^{- 2} ~\text{m}\)
4. \(1 . 73 \times10^{- 3} ~\text{m}\)
The speed of sound at a constant temperature depends on:
1. | Pressure | 2. | Density of gas |
3. | Above both | 4. | None of the above |
The velocity of sound in air is:
1. | faster in dry air than in moist air. |
2. | directly proportional to the pressure. |
3. | directly proportional to temperature. |
4. | independent of the pressure of air. |
\(4.0~\text{gm}\) of gas occupies \(22.4~\text{litres}\) at NTP. The specific heat capacity of the gas at a constant volume is \(5.0~\text{JK}^{-1}\text{mol}^{-1}.\) If the speed of sound in the gas at NTP is \(952~\text{ms}^{-1},\) then the molar heat capacity at constant pressure will be:
(\(R=8.31~\text{JK}^{-1}\text{mol}^{-1}\))
1. | \(8.0~\text{JK}^{-1}\text{mol}^{-1}\) | 2. | \(7.5~\text{JK}^{-1}\text{mol}^{-1}\) |
3. | \(7.0~\text{JK}^{-1}\text{mol}^{-1}\) | 4. | \(8.5~\text{JK}^{-1}\text{mol}^{-1}\) |
When height increases, the velocity of sound decreases:
1. | due to the decrease in pressure. |
2. | due to a decrease in temperature. |
3. | as a result of a decrease in both temperature and pressure |
4. | statement is wrong. |