Waves - NEET Physics Questions
Question 1: moderate

In a gaseous medium on increasing temperature 800 K, speed of sound becomes √5 times of initial then initial temperature of medium in °C is

1. 27Β°C
2. 300 Β°C
3. - 73Β°C
4. 73Β°C
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Question 2: moderate

For sound waves propagating in a medium, identify the property that is independent of the others :

1. Velocity
2. Wavelength
3. Frequency
4. All these depend on each other
View Answer

Speed of sound wave depends on medium and is independent of wavelength and frequency.

Question 3: moderate

Two waves of amplitude 2A and A of same frequency and velocity propogate in same direction with same phase. Then resultant amplitude is

1. 3A
2. √5A
3. √2A
4. A
View Answer

Resultant amplitude

\[ R= \sqrt{A^{2}+(2A)^{2}+ 2A.2A cos\theta} \]

As ΞΈ = 0ΒΊ

R= A+2A=3A

Question 4: moderate

Two waves of intensity I1 and I2 propagate in a medium in same direction. Then sum of maximum and minimum intensity is

1. \[ \left( \sqrt{I_{1}} -\sqrt{I_{2}}\right)^{2}\]
2. \[2 (I_{1}+I_{2}) \]
3. \[ (I_{1}+I_{2}) \]
4. \[ \left( \sqrt{I_{1}} +\sqrt{I_{2}}\right)^{2}\]
View Answer

\[ I _{max= }\left( \sqrt{I_{1}} +\sqrt{I_{2}}\right)^{2} \]

\[ I _{min = }\left( \sqrt{I_{1}} - \sqrt{I_{2}}\right)^{2} \]

\[ I _{max} + I _{min} = 2(I_{1} + I_{2})\]

Question 5: moderate

The fundamental frequency of a closed pipe is 220 Hz. If 1/4 of the pipe is filled with water, the frequency of the first overtone of the pipe now is

1. 220 Hz
2. 440 Hz
3. 880 Hz
4. 1760 Hz
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Question 6: moderate

An organ pipe P1 closed at one vibrating in its first overtone and another pipe P2 open at both ends vibrating in third overtone are in resonance with a given tuning fork. The ratio of the length of P1 to that of P2 is

1. 3/8
2. 8/3
3. 1/2
4. 1/3
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Question 7: moderate

A second harmonic has to be generated in a string of length l stretched between two rigid supports. The point where the string has to be plucked and touched are

1. Plucked at l/4 and touch at l/2
2. Plucked at l/4 and touch at 3l/4
3. Plucked at l/2 and touched at l/4
4. Plucked at l/2 and touched at 3l/4
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Question 8: moderate

A source of sound gives five beats per second when sounded with another source of frequency 100 s–1. The second harmonic of the source together with a source of frequency 205 s–1 gives five beats per second. What is the frequency of the source ?

1. 105 Hz
2. 205 Hz
3. 95 Hz
4. None of these
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Question 9: moderate

Ten tuning forks are arranged in increasing orderof frequency in such a way that any two nearest tuning forks produce 4 beats/sec. The highest frequency is twice of the lowest. Possible highest and the lowest frequencies are

1. 80 and 20
2. 100 and 50
3. 44 and 22
4. 72 and 36
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Question 10: moderate

Two coherent sources of different intensities send waves which interfere. The ratio of the maximum intensity to the minimum intensity is 25. The intensities are in the ratio

1. 25 : 1
2. 5:1
3. 9:4
4. 625:1
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