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General
Easy
Question
A Boat is travelling in a river with a speed 10 m/s along the stream flowing river through a rigid support. The wave length of the sound emitted from the transmitter inside the water is 14.45 mm. Assume that attenuation of sound in water and air is negligible (Temp of air & water =20°C. Density of river 
mean molecular wt of air =
and 
of air =1.4) Find frequency of sound detected by the receiver in air :
The correct answer is:
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As shown in the figure two sources producing sound 
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Range of number of beats received by observer O at rest is (nearly)
As shown in the figure two sources producing sound and (velocity of sound 360 m/sec ) each producing sound of frequency 200 Hz is rotating anti clock wise where as is approaching observer O each with a speed 10 m/sec. (neglect radius of circular path of ), then calculate
Range of number of beats received by observer O at rest is (nearly)
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A square ground of side 
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A square ground of side has a circular running track of radius a/2 with its centre coinciding the centre of the ground. A man is running on the track with an angular velocity while a car is moving on a road adjacent to ground as shown in the figure. The car moves in such away that the car, the man and the centre of the ground always lie on the same straight line. If a source of sound of frequency v=300 Hz is being placed at the centre of the ground find the minimum frequency received by the man in the car. Assume velocity of sound in air is v=330 m/s.
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Two straight parallel railway tracks are separated by a distance of 20 m. Two trains start simultaneously with speeds 54 km/hr in opposite directions from A and B as shown. They have identical frequencies of their horns which is 660 Hz. Find the frequency of the horn heard by any of the train driver due to the other, 15 min after the start
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the detector is at D. Find the maximum and minimum frequencies recorded. Velocity of sound in air at this temperature can be taken as 300 m/s
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A detector is released from rest over a source of sound of frequency 
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Maths-General
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If 
If
Maths-General
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Simplify 
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Maths-General
Maths-
If 
If
Maths-General
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The distance of the line 3x – y = 0 from the point (4, 1) measured along a line making an angle of 135º with the x – axis is
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Maths-General
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A stationary sound source 's' of frequency 334 Hz and a stationary observer ' O ' are placed near a reflecting surface moving away from the source with velocity 2 m/sec as shown in the figure. If the velocity of the sound waves is air is V=330 m/sec, the apparent frequency of the echo is
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Physics-General
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The speed of sound in a gas, in which two waves of wavelength 1.0 m and 1.02 m produce 6 beats per second, is approximately:
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Physics-General
