KVPY Sample Paper KVPY Stream-SX Model Paper-30

A source of frequency \['f'\] is stationary and an observer starts moving towards it at t = 0 with constant small acceleration. Then the variation of observed frequency f' registered by the observer with time is best represented as:

A)

B)

C)

D)

Correct Answer: A

Solution :

After a time t, velocity of observer \[{{V}_{0}}=at\]

\[\therefore {{f}_{0}}=\left( \frac{V+{{V}_{0}}}{V} \right){{f}_{s}}=\left( \frac{V+at}{V} \right){{f}_{s,}}\]

Which is straight the graph of positive slope