Question

Two identical straight wires are stretched so to produce 6 beats per second when vibrating simultaneously. On changing the tension slightly in one of them, the beat frequency remains unchanged. Denoting by T1 andT2 the higher and the lower initial tensions in the strings, then it could be said that while making the above changes in tension.

Solution

Correct option is

T2 was increased & T1 was decreased

Let V1 be the frequency of the wire having tension T1 and V2 that of wire having tension T2. Since  and  it follows that . Given V1 – V2 = 6. Now, if V­1 is decreased by 12 Hz to a value  remains unchanged, the number of beats per second would be  Also if V2 is increased by 12 Hz to a value  remains unchanged, then the number of beats per second would be  Hence, the beat frequency will remain unchanged if either T1 is decreased or T2 is increased.

SIMILAR QUESTIONS

Q1

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Q2

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Q3

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Q4

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Q5

A tuning fork of frequency 480 Hz produces 10 beats per second when sounded with a vibrating sonometer string. What must have been the frequency of the string if a slight increase in the tension of the string produces fewer beats per second than before?

Q6

A train blowing its whistle moves with a constant velocity u away from the observer on the ground. The ratio of the actual frequency of the whistle to that measured by the observer is found to be 1.2. If the train is at rest and the observer moves away from it at the same velocity, the ratio would be given by

Q7

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Q8

 

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Q9

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Q10

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