Physics (AS & A Level) · May / June 2018 · Paper 11 · Question 24

A binary star consists of two stars rotating around a common centre. Light from one of the stars is observed on the Earth. The observed frequency of the light varies between a minimum frequency $f_{\min}$ and a maximum frequency $f_{\max}$, as shown. The rate of rotation of the binary star increases. What is the change to $f_{\max}$ and the change to $f_{\min}$?

1. Adecreases, decreases
2. Bdecreases, increases
3. Cincreases, decreases
4. Dincreases, increases

As printed in the paper