SATHEE: Waves - Result Question 73

Waves - Result Question 73

75. The driver of a car travelling with speed $30 m / s e c$ towards a hill sounds a horn of frequency $600 H z$ . If the velocity of sound in air is $330 m / s$ , the frequency of reflected sound as heard by driver is

(a) $555.5 H z$

(b) $720 H z$

(d) $550 H z$

[2009]

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Answer:

Correct Answer: 75. (b)

Solution:

(b) From the given condition

$f^{'}$ is the apparent frequency received by an observer at the hill. $f^{''}$ is the frequency of the reflected sound as heard by driver.

$\begin{aligned} f^{'} & = \frac{v}{v - 30} f^{and} \\ f^{''} & = \frac{v + 30}{v} f^{'} \Rightarrow \frac{v + 30}{v - 30} f = \frac{360}{300} \times 600 \\ = 720 H z \end{aligned}$

Waves - Result Question 73

75. The driver of a car travelling with speed $30 m / s e c$ towards a hill sounds a horn of frequency $600 H z$ . If the velocity of sound in air is $330 m / s$ , the frequency of reflected sound as heard by driver is

Answer:

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Waves - Result Question 73

75. The driver of a car travelling with speed 30m/sec towards a hill sounds a horn of frequency 600Hz. If the velocity of sound in air is 330m/s, the frequency of reflected sound as heard by driver is

Answer:

Engineering Preparation

Medical Preparation

NCERT Books & Solutions

Important Resources

Other Resources

Syllabus

Test Platform

Sample Mock Test

Mentorship

NCERT Exercise Video Solution

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75. The driver of a car travelling with speed $30 m / s e c$ towards a hill sounds a horn of frequency $600 H z$ . If the velocity of sound in air is $330 m / s$ , the frequency of reflected sound as heard by driver is