Which of the below mentioned condition are necessary for beats?
Correct Answer :- a
Explanation : Beats occur whenever two sound sources emit sounds of slightly different frequencies. Perhaps you recall the demonstration in class with the two tuning forks of slightly different frequencies.
Choose the correct statements for standing waves.
The correct answers are: There is no transport of energy along a standing wave, Each particle on a string (on which a standing wave is travelling) is oscillating with frequency common to the two superposing waves., The amplitude of each point on such string depends on the location of the point
Choose the correct statem ents
The correct answers are: Phase velocity can be greater than the speed of light., Phase velocity is only a mathematical concept, Phase velocity represents the speed at which a given phase of monochromatic wave train advances.
Choose the correct statements when both the source & detector are in motion
The correct answers are: The frequency observed can be greater than the actual frequency, The frequency observed can be less than the actual frequency
Choose the correct statements
The correct answers are: In a non dispersive medium, group velocity is equal to phase velocity., In a dispersive medium, the two velocity are not the same
Two identical sources P and Q emit waves in phase and of same wavelength λ. Spacing between P and Q is 3λ. The maximum distance from P along the horizontal for which minimum occurs is given by
Select the correct options
The correct answers are: Interference is superposition of travelling waves in space., Beats is superposition of travelling waves in time.
Maximum change in the frequency is observed in which of the following conditions
The correct answers are: Source & detector move towards each other, Source & detector move away from each other
Choose the correct options
Correct Answer :- a
Explanation : a) For the formation of stationary waves, it is necessary that the medium should not be unlimited but it should have a boundary. The wave propagating in such a medium will reflect at the boundary and produce a wave of the same kind travelling in the opposite direction. The position of two waves will give rise to a stationary wave. At the free end, the transverse wave is reflected without change of phase. Hence an essential requirement for the formation of stationary waves is that the medium must be bounded, having definite boundaries. In stationary waves, there are certain points of the medium, which are permanently at rest.
Chose the correct statement for standing waves
The correct answers are: Standing waves are stationary in space, The two superposing waves must have the same frequency speed but might have different amplitudes