Student Login

Home›Chapters›Wave Motion PYQs›Doppler Effect›Question 59

NEET 2017 · Doppler Effect

Doppler Effect question from NEET 2017

Q59NEET 2017Easy

Doppler Effect

Two cars moving in opposite directions approach each other with speed of 22 ms ${}^{-1}$ and 16.5 m s ${}^{-1}$ respectively. The driver of the first car blows a horn having a frequency 400 Hz. The frequency heard by the driver of the second car is (velocity of sound is 340 m s ${}^{-1}$ )

Show answer and solution

Answer: (c)

Both approaching: $n' = n\frac{v + v_o}{v - v_s}$ , with $v_s = 22$ m/s, $v_o = 16.5$ m/s.
$n' = 400 \times \frac{340 + 16.5}{340 - 22} = 400 \times \frac{356.5}{318}$
$n' \approx 448$ Hz. So the answer is (c) 448 Hz.

Report a mistake

More questions on Doppler Effect

An observer is moving with half the speed of light towards a stationary microwave source…JEE Main 2017
Two engines pass each other moving in opposite directions with uniform speed of 30 m/s…JEE Main 2016 (9 Apr, Shift 1)
A siren emitting a sound of frequency 800 Hz moves away from an observer towards a cliff…NEET 2016 (Phase 1)
A toy-car, blowing its horn, is moving with a steady speed of 5 m/s, away from a wall. An…JEE Main 2016 (10 Apr, Shift 1)
A source of sound S emitting waves of frequency 100 Hz and an observer O are located at…NEET 2015 (AIPMT)
A bat moving at 10 ms ⁻¹ towards a wall sends a sound signal of 8000 Hz towards it. On…JEE Main 2015 (10 Apr, Shift 1)
A source of sound emits sound waves at frequency f0. It is moving towards an observer…JEE Main 2015 (11 Apr, Shift 1)
A train is moving on a straight track with speed 20 ms⁻¹. It is blowing its whistle at…JEE Main 2015