Kinematics · JEE Main previous year questions

2015 1 question

1. Q582015 · 4 Apr 2015 · Shift 1

   A train is moving on a straight track with speed $20\mathrm{m}{\mathrm{s}}^{-1}$. It is blowing its whistle at the frequency of $1000\mathrm{Hz}$. The percentage change in the frequency heard by a person standing near the track as the train passes him is (speed of sound $=320\mathrm{m}{\mathrm{s}}^{-1}$) close to :

   1. A.$18\%$
   2. B.$24\%$
   3. C.$6\%$
   4. D.$12\%$
   Show answer

   Answer: D