# GENERAL KNOWLEDGE

## GK

### BIG BANG THEORY

 Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
How is the Doppler Effect used in exploration of the universe?
 A To measure a change in the speed of light as the source moves relative to the observer B To measure a change in brightness of light as the source moves relative to the observer C To measure a change in the frequency of light as the source moves relative to the observer D None of the above
Explanation:

Detailed explanation-1: -Redshift is an example of the Doppler Effect. As an object moves away from us, the sound or light waves emitted by the object are stretched out, which makes them have a lower pitch and moves them towards the red end of the electromagnetic spectrum, where light has a longer wavelength.

Detailed explanation-2: -The waves travel at the same speed, but the observed frequency depends on any relative motion between the observer and source. When the observed frequency changes, so does the wavelength. If the observer and source are moving toward each other, then the frequency increases and the wavelength decreases.

There is 1 question to complete.