A whistle emitting a sound of frequency 440 Hz is tied to a string of 1.5 m leng

Sail E0 Webinar

Question

A whistle emitting a sound of frequency 440 Hz is tied to a string of 1.5 m length and rotated with an angular velocity of 20 rad/s in the horizontal plane. Then the range of frequencies heard by an observer stationed at a large distance from the whistle will be (v = 330 m/s)

Options:

A . 400.0 Hz to 484.0 Hz

B . 403.3 Hz to 480.0 Hz

C . 400.0 Hz to 480.0 Hz

D . 403.3 Hz to 484.0 Hz

Answer: Option D
:
D
Frequency heard by the observes will be maximum when the source is in position D. In this case, source will be approaching towards the stationary observer, almost along the line of sight (as observer is stationed at a larger distance).

n_{m a x} = \frac{v}{v - v_{s}} n = \frac{330 \times 440}{330 - 1.5 \times 20} = 484 H z

A Whistle Emitting A Sound Of Frequency 440 Hz Is Tied To A ...

Similarly, frequency heard by the observer will be minimum when the source reaches at position B. now, the source will be moving away from the observer.

n_{m a x} = \frac{v}{v + v_{s}} \times n = \frac{330}{330 + 1.5 \times 20} \times 440 = \frac{330 \times 440}{360} = 403.3 H z

Was this answer helpful ?

Next Question

Submit Solution

More Questions on This Topic :

Question 1. A man standing on a platform hears the sound of frequency 605 Hz coming from 550 Hz train whistle moving towards th....sound is 330 m/s. What is the speed of train?

Question 2. A source of sound S is moving with a velocity 50 m/s towards a stationary observer. He measures the frequency of th....The velocity of the sound in the medium is 350 m/s.

Question 3. A band playing music at frequency f is moving towards a wall at a speed vb. A motorist is following the band with a spe....the expression for the beat frequency heard by the motorist is

Question 4. Speed of sound wave is v. If a reflector moves towards a stationary source emitting waves of frequency f with speed....with speed u, the wavelength of reflected waves will be

Question 5. The sound from a very high burst of fireworks takes 5 s to arrive at the observer. The burst occurs 1662 m above th....20∘C. Then (assume velocity of sound at 0∘C is 330 m/s)

Question 6. The frequency changes by 10% as the source approaches a stationary observer with constant speed Vs. What should be ....Vs ≪ v(v is the speed of sound in air).

Question 7. For a sound wave travelling towards +x direction, sinusoidal longitudinal displacement ξ at a certain time is given as....of air is B=5×105N/m2, the variation of pressure excess will be

Question 8. In the figure shown, a source of sound of frequency 510 Hz moves with constant velocity = 20 m/s in the direction s....equal to (speed of sound relative to air is 330 m/s)

Question 9. A wall is moving with velocity u and a source of sound moves with velocity u/2 in the same direction as shown in the fi....the reflected sound wavelength by the wall is equal to

Question 10. A train is moving in an elliptical orbit in anticlockwise sense with a speed of 110 m/s. Guard is also moving in the giv....by guard is (velocity of sound v = 330 m/s)

Chapter 1 - GLOBAL STEEL SCENARIO & INDIAN STEEL INDUSTRY Part 1 : (13-04-2024) INDUSTRY AND COMPANY AWARENESS (ICA)

Direction Sense Test Part 1 Reasoning (Hindi)

Chapter 1 - RMHP / OHP / OB & BP Part 1 : (14-02-2024) GPOE

Cube & Cuboid Part 1 Reasoning (Hindi)

Data Interpretation (DI) Basic Concept Reasoning (Hindi)

Counting Figures Part 1 Counting Of Straight Lines Reasoning (Hindi)

Sail E0 free webinar Webinars

Real Numbers Part 7 Class 10 Maths

Real Numbers Part 1 Class 10 Maths

Polynomials Part 1 Class 10 Maths

Pie Chart - Test Paper 1 Data Interpretation Reasoning & DI

Tabulation - Test Paper 2 Data Interpretation Reasoning & DI

Test Paper 1 Direction Sense Test Reasoning & DI

ICA , RDIC,GFM Free Modal Test Paper - Non - Technical Branch Old Syllabus 2022 - SAIL Junior Officer E0

GFM Combined 1 Free Revision Test SAIL JO E-0