CBSE
Multiple Choice QuestionsAstronomical wavelength increase due to doppler effect known as
Red shift
Voilet shift
UV
IR shift
Let T1 and T2 be the time periods of springs A and B when mass M is suspended from one ·end of each spring. If both springs are taken in series and the same mass M is suspended from the series combination, the time period is T then
T1 + T2 +T3
T2 =
The equation of a progressive wave is given by y = 5 sin where y and x are in m and t is in s
(1) The amplitude of the wave is 5 m.
(2) The wavelength of the wave is 5 m.
(3) The frequency of the wave is 50 Hz.
(4) The velocity of the wave is 250 m s-1
Which of the following statements are correct?
(1), (2) and (3)
(2) and (3)
(1) and (4)
All are correct
Assertion: The fundamental frequency of an open organ pipe increases as the temperature is increased.
Reason: This is because as the temperature increases, the velocity of sound increases more rapidly than length of the pipe.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
The second overtone of an open pipe has the same frequency as the first overtone of a closed pipe 2 m long. The length of the open pipe is
8 m
4 m
2 m
1 m
A uniform string is vibrating with a fundamental frequency ' f ' . The new frequency, if radius & length both are doubled would be
2f
3f
Two waves represented by y = a sin( ωt - kx ) and y = a cos( ωt- kx ) are superposed. The resultant wave will have an amplitude
a
2 a
zero
What is your observation when two sources are emitting sound with frequency 499 Hz and 501 Hz?
Frequency of 500 Hz is heard with change in intensity take place twice.
Frequency of 500 Hz is heard with change in intensity take place once.
Frequency of 2 Hz is heard with change in intensity take place once.
Frequency of 2 Hz is heard with change in intensity take place twice.
Four massless springs whose force constants are 2k, 2k, k and 2k respectively are attached to a mass M kept on a frictionless plane as shown in the figure. If the mass M is displaced in the horizontal direction, then the frequency of the system is
Assertion: To hear distinct beats, difference in frequencies of two sources should be less than 10.
Reason: More the number of beats per sec
more difficult to hear them.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
