| A source of sound is moving eastward in still air. Wavelength of the waves to the east of the source is $λ_E$ and to the west of the source is $λ_W$ |
| A) $λ_E=λ_W$ | B) $λ_E<λ_W$ | C) $λ_E>λ_W$ | D) Any of these |
| A source of sound is moving eastward in air blowing eastward. Wavelength of the waves to the east of the source is $λ_E$ and to the west of the source is $λ_W$ |
| A) $λ_E=λ_W$ | B) $λ_E<λ_W$ | C) $λ_E>λ_W$ | D) Any of these |
| A source of sound is moving eastward in still air at a speed greater than the speed of sound in the medium. Wavelength of the waves in front of the source is $λ_F$ and to the back of the source is $λ_B$ |
| A) $λ_F=λ_B$ | B) $λ_F<λ_B$ | C) $λ_F>λ_B$ | D) None of these |
| A boat is moving in a large lake at a speed greater than the speed of the waves on the surface of water. |
| A) waves in the form of ripples spread out in all directions. |
| B) waves in the form of ripples spread out only in the forward direction. |
| C) A triangular wake is formed on the water's surface with a thin leading edge |
| D) A triangular wake is formed on the water's surface with a thick leading edge. |
| An observer is moving towards a stationary source. |
| A) wave length of the waves ahead of him will be smaller than the wavelength of the waves behind him. |
| B) wave length of the waves ahead of him will be greater than the wavelength of the waves behind him. |
| C) wave length of the waves ahead of him and the wavelength of the waves behind him will be same. |
| D) Any of these depending on the frequency of the source. |
| When a vibrating tuning fork of frequency n moves in air. |
| A) It starts vibrating at a frequency less than n |
| B) It starts vibrating at a frequency greater than n. |
| C) frequency of vibration may be less than or greater than n. |
| D) frequency of vibration does not change as it moves. |
| A boat is moving in a large lake at a speed greater than the speed of the waves on the surface of water. |
| A) waves in the form of ripples spread out in all directions. |
| B) waves in the form of ripples spread out only in the forward direction. |
| C) A triangular wake is formed on the water's surface with a thin leading edge |
| D) A triangular wake is formed on the water's surface with a thick leading edge. |
| An observer is moving towards a stationary source. |
| A) wave length of the waves ahead of him will be smaller than the wavelength of the waves behind him. |
| B) wave length of the waves ahead of him will be greater than the wavelength of the waves behind him. |
| C) wave length of the waves ahead of him and the wavelength of the waves behind him will be same. |
| D) Any of these depending on the frequency of the source. |
| When a vibrating tuning fork of frequency n moves in air. |
| A) It starts vibrating at a frequency less than n |
| B) It starts vibrating at a frequency greater than n. |
| C) frequency of vibration may be less than or greater than n. |
| D) frequency of vibration does not change as it moves. |