Waves - Result Question 68

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70. Two cars moving in opposite directions approach each other with speed of $22 m / s$ and $16.5 m / s$ 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 $340 m / s$ ] : [2017]

======= ####70. Two cars moving in opposite directions approach each other with speed of $22 m / s$ and $16.5 m / s$ 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 $340 m / s$ ] : [2017]

3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/waves/waves—result-question-68.md (a) $361 Hz$

(b) $411 Hz$

(c) $448 Hz$

(d) $350 Hz$

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Answer:

Correct Answer: 70. (c)

Solution:

  1. (c) As we known from Doppler’s Effect

$f _{\text{apprent }}=f_0[\frac{v+v_0}{v-v_s}]=400[\frac{340+16.5}{340-22}]$

$f _{\text{apprent }}=448 Hz$

$A \xrightarrow[f_0=400 Hz]{V_s=22 m / s} \stackrel{V_0=16.5 m / s}{\stackrel{ }{\circ}} B$