Physics-
General
Easy
Question
An engine approaches a hill with a constant speed. When it is at a distance of 
it blows a whistle, whose echo is heard by the driver after 
If speed of sound in air is 
the speed of engine is
The correct answer is:
If the speed of engine is 
the distance traveled by engine in 
will be 
and hence the distance traveled by sound in reaching the hill and coming back to the moving driver
So the time interval between original sound and it’s echo
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When the tension of the string is slightly increased the beat frequency is found to be 
If the frequency of is 
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is:
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A transverse sinusoidal wave moves along a string in positive x-direction at a speed of 10
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The point on the line x – y + 2 = 0 from which the tangent to the parabola y2 = 8x is perpendicular to the given line is (a, b), then the line ax + by + c = 0 is
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If the speed of the wave shown in the figure is 
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The equations of the normals at the ends of the latus rectum of the parabola y2 = 4ax are given by
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The driver of a car travelling with speed 30 metres per second towards a hill sounds a horn of frequency 
If the velocity of sound in air is 330 metres per second, the frequency of the reflected sound as heard by the driver is
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physics-General
