Physics-
General
Easy
Question
Radio waves coming at 
to vertical are received by a radar after reflection from a nearby water surface & directly. What can be height of antenna from water surface so that it records a maximum intensity (a maxima). (wavelength = 
) (Assume phase changes by 
after reflection)
The correct answer is:
Related Questions to study
Physics-
Equation of a stationary and a travelling waves are as follows y1 = a sin kx cos 
t and y2 = a sin (t – kx). The phase difference between two points
in the standing wave (y1 ) andis f2 in travelling wave (y2 ) then ratio
Equation of a stationary and a travelling waves are as follows y1 = a sin kx cos t and y2 = a sin (t – kx). The phase difference between two pointsin the standing wave (y1 ) andis f2 in travelling wave (y2 ) then ratio
Physics-General
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Earthquakes generate sound waves inside Earth. Unlike a gas, Earth can experience both transverse (S) and longitudinal (P) sound waves. Typically, the speed of S waves is about 4 km/s. A seismograph records P and S waves from an earthquake. The first P waves arrive 3.0 min before the first S wave (figure). Assuming the waves travel in a straight line, how far away does the earthquake occur ? (Yearth = 12.8 
1010 pa, rearth = 2000 kg/m3 )
Earthquakes generate sound waves inside Earth. Unlike a gas, Earth can experience both transverse (S) and longitudinal (P) sound waves. Typically, the speed of S waves is about 4 km/s. A seismograph records P and S waves from an earthquake. The first P waves arrive 3.0 min before the first S wave (figure). Assuming the waves travel in a straight line, how far away does the earthquake occur ? (Yearth = 12.8 1010 pa, rearth = 2000 kg/m3 )
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Figure shows a stretched string of length L and pipes of length L, 2L, L/2 and L/2 in options (A), (B), (C) and (D) respectively. The string’s tension is adjusted until the speed of waves on the string equals the speed of sound waves in the air. The fundamental mode of oscillation is then set up on the string. In which pipe will the sound produced by the string cause resonance ?
Figure shows a stretched string of length L and pipes of length L, 2L, L/2 and L/2 in options (A), (B), (C) and (D) respectively. The string’s tension is adjusted until the speed of waves on the string equals the speed of sound waves in the air. The fundamental mode of oscillation is then set up on the string. In which pipe will the sound produced by the string cause resonance ?
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For a sound wave travelling towards +x direction, sinusoidal longitudinal displacement x at a certain time is given as a function of x. If Bulk modulus of air is B = 5 x 105 N/m2 , the variation of pressure excess will be
For a sound wave travelling towards +x direction, sinusoidal longitudinal displacement x at a certain time is given as a function of x. If Bulk modulus of air is B = 5 x 105 N/m2 , the variation of pressure excess will be
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A 100 m long rod of density 10.0 x 104 kg/m3 and having Young’s modulus Y = 1011 Pa, is clamped at one end. It is hammered at the other free end. The longitudinal pulse goes to right end, gets reflected and again returns to the left end. How much time, the pulse take to go back to initial point.
A 100 m long rod of density 10.0 x 104 kg/m3 and having Young’s modulus Y = 1011 Pa, is clamped at one end. It is hammered at the other free end. The longitudinal pulse goes to right end, gets reflected and again returns to the left end. How much time, the pulse take to go back to initial point.
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S1 and S2 are two coherent sources of sound separated by distance 100.25 , where is the wave length of sound. S1 leads S2 in phase by /4. A and B are two points on the line joining S1 and S2 as shown in figure. The ratio of amplitudes of source S1 and S2 are in ratio 1:2. The ratio of intensity at A to that of B 
is
S1 and S2 are two coherent sources of sound separated by distance 100.25 , where is the wave length of sound. S1 leads S2 in phase by /4. A and B are two points on the line joining S1 and S2 as shown in figure. The ratio of amplitudes of source S1 and S2 are in ratio 1:2. The ratio of intensity at A to that of B is
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When beats are produced by two progressive waves of nearly the same frequency, which one of the following is correct?
When beats are produced by two progressive waves of nearly the same frequency, which one of the following is correct?
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S1 & S2 are two coherent sources of sound having no initial phase difference. The velocity of sound is 330 m/s. No minima will be formed on the line passing through S2 and perpendicular to the line joining S1 and S2 , if the frequency of both the sources is :
S1 & S2 are two coherent sources of sound having no initial phase difference. The velocity of sound is 330 m/s. No minima will be formed on the line passing through S2 and perpendicular to the line joining S1 and S2 , if the frequency of both the sources is :
Physics-General
Physics-
A wall is moving with velocity u and a source of sound moves with velocity u/2 in the same direction as shown in the figure. Assuming that the sound travels with velocity 10u. The ratio of incident sound wavelength on the wall to the reflected sound wavelength by the wall, is equal to
A wall is moving with velocity u and a source of sound moves with velocity u/2 in the same direction as shown in the figure. Assuming that the sound travels with velocity 10u. The ratio of incident sound wavelength on the wall to the reflected sound wavelength by the wall, is equal to
Physics-General
Physics-
In the figure shown a source of sound of frequency 510 Hz moves with constant velocity vs = 20 m/s in the direction shown. The wind is blowing at a constant velocity vw = 20 m/s towards an observer who is at rest at point B. Corresponding to the sound emitted by the source at initial position A, the frequency detected by the observer is equal to (speed of sound relative to air = 330 m/s)
In the figure shown a source of sound of frequency 510 Hz moves with constant velocity vs = 20 m/s in the direction shown. The wind is blowing at a constant velocity vw = 20 m/s towards an observer who is at rest at point B. Corresponding to the sound emitted by the source at initial position A, the frequency detected by the observer is equal to (speed of sound relative to air = 330 m/s)
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A source of sound of frequency 256 Hz is moving rapidly towards a wall with a velocity of 5 m/sec. If sound travels at a speed of 330 m/sec, then number of beats per second heard by an observer between the wall and the source is:
A source of sound of frequency 256 Hz is moving rapidly towards a wall with a velocity of 5 m/sec. If sound travels at a speed of 330 m/sec, then number of beats per second heard by an observer between the wall and the source is:
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Physics-
y - x curve at an instant for a wave travelling along x axis on a string is shown. Slope at the point A on the curve, as shown, is 53°.
y - x curve at an instant for a wave travelling along x axis on a string is shown. Slope at the point A on the curve, as shown, is 53°.
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For a certain transverse standing wave on a long string, an antinode is formed at x = 0 and next to it, a node is formed at x = 0.10 m. the displacement y(t) of the string particle at x = 0 is shown in figure
For a certain transverse standing wave on a long string, an antinode is formed at x = 0 and next to it, a node is formed at x = 0.10 m. the displacement y(t) of the string particle at x = 0 is shown in figure
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A wire, under tension between two fixed points A and B, executes transverse vibrations so that the midpoint O of AB is a node. Then:
A wire, under tension between two fixed points A and B, executes transverse vibrations so that the midpoint O of AB is a node. Then:
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There are three strings RP, PQ and QS as shown. Their mass and lengths are RP = (0.1Kg, 2m), PQ = (0.2 Kg, 3 m), QS = (0.15 Kg, 4 m) respectively. All the strings are under same tension. Wave-1 is incident at P. It is partly reflected (wave-2) and partly transmitted (wave-3). Now wave-3 is incident at Q. It is again partly transmitted (wave-5) and partly reflected (wave-4). Phase difference between wave-1 and wave :
There are three strings RP, PQ and QS as shown. Their mass and lengths are RP = (0.1Kg, 2m), PQ = (0.2 Kg, 3 m), QS = (0.15 Kg, 4 m) respectively. All the strings are under same tension. Wave-1 is incident at P. It is partly reflected (wave-2) and partly transmitted (wave-3). Now wave-3 is incident at Q. It is again partly transmitted (wave-5) and partly reflected (wave-4). Phase difference between wave-1 and wave :
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