Offline paper
Physics · 2015
JEE Main 2015 · 2015-04-04 Offline · Q13
A train is moving on a straight track with speed 20 ms^-1. It is blowing its whistle at the frequency of 1000 Hz. The percentage change in the…
A train is moving on a straight track with speed $\displaystyle 20 \mathrm{~ms}^{-1}$. It is blowing its whistle at the frequency of $\displaystyle 1000$ Hz. The percentage change in the frequency heard by a person standing near the track as the train passes him is (speed of sound $\displaystyle =320 \mathrm{~ms}^{-1}$ ) close to :
Official answer
(2)
$\displaystyle 12$%
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JEE Main 2015 Physics question, with the answer from NTA’s final answer key. Where our answers come from.