The separation between a node and the next antinode in a vibrating air column is \(20\) cm. The speed of sound is \(320\) m/s. The frequency of sound is:
1. \(128\) Hz
2. \(256\) Hz
3. \(400\) Hz
4. \(800\) Hz
The intensity \((I)\) of a sound wave depends on the distance \((x)\) from the source as:
1. \(I\propto x\)
2. \(I\propto \frac1x\)
3. \(I\propto \frac1{x^2}\)
4. None of the above
A rope of uniform mass per unit length \(\mu\) is suspended from the ceiling, hanging under its own weight. If a small transverse pulse is formed at its lower end A, it travels upward with a local speed \(v=\sqrt {\dfrac{\text{tension}}{\text{mass/length}}}\).
The speed of the pulse is:
1. | maximum at A, minimum at O |
2. | minimum at A, maximum at O |
3. | uniform |
4. | minimum at A and O, maximum in the middle |
Assertion (A): | Sound waves in a gas are pressure waves, but these are also accompanied by changes in local temperature. |
Reason (R): | This is due to the fact that sound waves are propagated in gas through an adiabatic process, and hence accompanied by temperature variations. |
1. | Both (A) and (R) are True and (R) is the correct explanation of (A). |
2. | Both (A) and (R) are True but (R) is not the correct explanation of (A). |
3. | (A) is True but (R) is False. |
4. | (A) is False but (R) is True. |
The speed of sound in a medium depends on:
1. | the elastic property but not on the inertia property |
2. | the inertia property but not on the elastic property |
3. | the elastic property as well as the inertia property |
4. | neither the elastic property nor the inertia property |
Which of the following statement is correct?
1. | The energy of any small part of a string remains constant in a travelling wave. |
2. | The energy of any small part of a string remains constant in a standing wave. |
3. | The energies of all the small parts of equal length are equal in a travelling wave. |
4. | The energies of all the small parts of equal length are equal in a standing wave. |
A wave moving in a gas:
1. | must be longitudinal | 2. | may be longitudinal |
3. | must be transverse | 4. | may be transverse |
Velocity of sound in air is \(332\) m/s. Its velocity in the vacuum will be:
1. \(>332\) m/s
2. \(=332\) m/s
3. \(<332\) m/s
4. meaningless
Two strings \(A\) and \(B,\) made of same material, are stretched by same tension. The radius of string \(A\) is double of the radius of \(B.\) A transverse wave travels on \(A\) with speed \(v_A\) and on \(B\) with speed \(v_B.\) The ratio \(\frac{v_A}{v_B}=\) ?
1. | \(\frac{1}{2}\) | 2. | \(2\) |
3. | \(\frac{1}{4}\) | 4. | \(4\) |
Which of the following is a mechanical wave?
1. | Radio waves | 2. | X-rays |
3. | Light waves | 4. | Sound waves |