A) 9 : 8
B) 8 : 9
C) 1:1
D) 9 :10
Correct Answer: A
Solution :
Apparent frequency when source is coming closer to observer \[{{v}_{c}}=\left( \frac{v}{v-{{v}_{s}}} \right)v\] ?.(i) Apparent frequency when source is moving away from observer \[{{v}_{f}}=\left( \frac{v}{v+{{v}_{s}}} \right)v\] ?..(ii) From two equations \[\frac{{{v}_{c}}}{{{v}_{f}}}=\frac{v+{{v}_{s}}}{v-{{v}_{s}}}\] \[=\frac{340+20}{340-20}=\frac{9}{8}\] So, \[{{v}_{c}}:{{v}_{f}}=9:8\]You need to login to perform this action.
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