Doppler Effect | MCQs

Explanation

"Blueshift" is a term that astronomers use to describe an object that is moving toward another object or toward us.

Someone will say, "That galaxy is blueshifted with respect to the Milky Way",

for example. It means that the galaxy is moving toward our point in space

Explanation

Explanation

When a police car with its siren on moves towards a stationary listener, the frequency of the sound perceived by the listener increases.

This phenomenon is known as the Doppler effect.

Explanation

The Doppler effect is applicable to all types of waves, including sound waves, light waves, and even water waves.

It describes the change in frequency or wavelength of a wave when there is relative motion between the wave source and the observer. 

Explanation

When Bilal moves away from a stationary organ producing a sound of frequency 'f' with a speed equal to 0.5 times the speed of sound, he will hear a sound of lower frequency.

This phenomenon is known as the Doppler effect.

To calculate the frequency of the sound Bilal hears, we can use the following formula:

f' = f * (v + vL) / (v + vS)

Where:

- f' is the frequency of the sound heard by Bilal

- f is the frequency of the sound produced by the stationary organ

- v is the speed of sound

- vL is the speed of Bilal

- vS is the speed of the source (in this case, the stationary organ)

Since Bilal is moving away from the source, vS is negative.

We substitute the values into the formula:

f' = f * (v - 0.5v) / (v - (-v))

Simplifying the equation:

f' = f * (0.5v) / (2v)

f' = f * 0.5 / 2

f' = f * 0.25