Advertisements
Advertisements
प्रश्न
Two sitar strings A and B playing the note ‘Ga’ are slightly out of tune and produce beats of frequency 6 Hz. The tension in the string A is slightly reduced and the beat frequency is found to reduce to 3 Hz. If the original frequency of A is 324 Hz, what is the frequency of B?
Advertisements
उत्तर १
Frequency of string A, fA = 324 Hz
Frequency of string B = fB
Beat’s frequency, n = 6 Hz
Beat's Frequency is given as:
`n = |f_A +- f_B|`
`6 = 324 +- f_B`
`F_B = 330 "Hz" or 318 "Hz"`
Frequency decreases with a decrease in the tension in a string. This is because frequency is directly proportional to the square root of tension. It is given as:
`v prop sqrtT`
Hence the beat frequency cannot be 330 Hz
`:.f_n = 318Hz`
उत्तर २
Let υ1 and υ2 be the frequencies of strings A and B respectively.
Then, υ1 = 324 Hz, υ2 = ?
Number of beats, b = 6
υ2 = υ1 ± b = 324 ± 6 !.e., υ2 = 330 Hz or 318 Hz
Since the frequency is directly proportional to square root of tension, on decreasing the tension in the string A, its frequency υ1 will be reduced i.e., number of beats will increase if υ2 = 330 Hz. This is not so because number of beats become 3.
Therefore, it is concluded that the frequency υ2 = 318 Hz. because on reducing the tension in the string A, its frequency may be reduced to 321 Hz, thereby giving 3 beats with υ2 = 318 Hz.
APPEARS IN
संबंधित प्रश्न
In Doppler effect of light, the term “red shift” is used for ______.
(A) frequency increase
(B) frequency decrease
(C) wavelength decrease
(D) frequency and wavelength increase
The working of RADAR is based on ...............
a) resonance
b) speed of a star
c) Doppler effect
d) speed of rotation of sun
Explain the production of beats and deduce analytically the expression for beats frequency.
When the observer moves towards the stationary source with velocity, 'V1', the apparent frequency of the emitted note is 'F1'. When the observer moves away from the source with velocity 'V1', the apparent frequency is 'F2'. If 'V' is the velocity of sound in air and `"F"_1/"F"_2 = 4` then `"V"/"V"_1 = ?`
If two tuning forks A and B are sounded together, they produce 4 beats per second. When A is slightly loaded with wax, they produce 2 beats when sounded again. The frequency of A is 256 Hz. The frequency of B will be ______
A tuning fork 'A' produces 5 beats per second with a tuning fork of frequency 480 Hz. When a little wax is stuck to a prong of fork A, the number of beats heard per second becomes 2. What is the frequency of tuning fork A before the wax is stuck to it?
Two waves of wavelength 2 m and 2.02 m, with the same speed superimpose to produce 2 beats per second. The speed of each wave is ____________.
For formation of beats, two sound notes must have ______.
Two tuning forks have frequencies 380 Hz and 384 Hz respectively. When they are sounded together, maximum sound is heard. How long will it take to hear the minimum sound?
A set of 56 tuning forks are arranged in series of increasing frequencies. If each fork gives 4 beats with preceding one and the frequency of the last is twice than than that of first, then frequency of the first fork is ____________.
A pipe closed at one end has a length of 1m and at its open end, 0.25 m long uniform string is vibrating in its third harmonic and resonates with a fundamental frequency of pipe. If the tension in the string is 100 N and the speed of sound is 340 `m/s`, then the mass of the string is near ______
A pipe open at both ends has a length of 1m. The air column in the pipe can not resonate for a frequency (Neglect end correction, speed of sound in air = 340 m/s)
Two wires are producing fundamental notes of the same frequency. Change in which of the following factors of one wire will NOT produce beats between them?
The frequency of two tuning forks A and B are 1.5% more and 2.5% less than that of the tuning fork C. When A and B are sounded together, 12 beats are produced in 1 second. The frequency of tuning fork C is ______
A tuning fork A, marked 512 Hz, produces 5 beats per second, where sounded with another unmarked tuning fork B. If B is loaded with wax the number of beats is again 5 per second. What is the frequency of the tuning fork B when not loaded?
Wire having tension 225 N produces six beats per second when it is tuned with a fork. When tension changes to 256 N, it is tuned with the same fork, the number of beats remain unchanged. The frequency of the fork will be ______.
If beat frequency is 2 Hz, what is the time interval between success waxings?
One beat means that the intensity of sound should be ______.
