While walking on the Moon, you cannot hear the sound of stones cracking behind you because:
| 1. | Sound waves need a medium to travel through. |
| 2. | Sound waves are transverse. |
| 3. | The acceleration due to gravity on the Moon is very small. |
| 4. | Sound waves are longitudinal. |
A wave travelling in the positive x-direction having maximum displacement along y-direction as 1m, wavelength 2π m and frequency of 1/π Hz is represented by
1. y=sin(x-2t)
2. y=sin(2πx-2πt)
3. y=sin(10πx-20πt)
4. y=sin(2πx+2πt)
| Column-I | Column-II | Column-III | |||||
| (A) | \(\small0.04\sin(10x+600t) \) | (P) | sinusoidal waveform | (I) | speed \(=30~\text{m/s}\) | ||
| (B) | \(\small0.008\sin^2(10x-300t)\) | (Q) | wave pulse | (II) | speed \(=60~\text{m/s}\) | ||
| (C) | \(\small\dfrac{3\times10^{-3}}{(10x+600t)^2+400}\) | (R) | combination of waveforms | (III) | moving along positive \(x\) | ||
| (D) | \(\small(2\times10^{-3})\sin10x \cdot\cos300t\) | (IV) | moving along negative \(x\) | ||||
| (V) | moving in the opposite direction | ||||||
| 1. | A-P,II,III; B-Q,I,IV; C-Q,II,III; D-R,I |
| 2. | A-P,II,IV; B-P,I,III; C-Q,II,IV; D-R,I,V |
| 3. | A-P,I,III; B-Q,I,IV; C-R,III; D-R,I,IV |
| 4. | A-P,I,III; B-Q,I,III; C- R-II,IV; D-R,I,V |
| 1. | its frequency changes |
| 2. | its wavelength changes |
| 3. | both frequency and wavelength change |
| 4. | both frequency and wavelength remain unchanged |
Which of the following is not possible for sound waves in air?
1. beats
2. interference
3. diffraction
4. polarization
| 1. | \(3~\text {m/s}\) | 2. | \(4~\text {m/s}\) |
| 3. | \(12~\text {m/s}\) | 4. | \(48~ \text {m/s}\) |
When sound wave is refracted from air to water, which of the following will remain unchanged?
1. Wave number
2. Wavelength
3. Wave velocity
4. Frequency
The equation \(y=A \text{cos}(kx-\omega t )\) represents a wave motion with:
| 1. | amplitude \(A\), frequency \(\dfrac{\omega}{2\pi}\) |
| 2. | amplitude \(\dfrac{A}{2}\), frequency \(\dfrac{2\omega}{\pi}\) |
| 3. | amplitude \(2A,\) frequency \(\dfrac{\omega}{4\pi}\) |
| 4. | does not represent a wave motion |