Waves 11.

According to Newton sound travel in air under the

For answer keys visit our YT channel conditions of
https://youtube.com/@drmohsinjaved A. Adiabatic
B. Isothermal
1. Waves transmit __________________ from one place to C. Isobaric
another D. Isochoric
A. Energy
B. Mass 12. Sound waves do not travel in a vacuum because
C. Both A. They are transverse waves
D. None B. They are stationary waves
C. They require a material medium for propagation
2. The waves that require a material medium for their D. They do not have enough energy
propagation are called
A. Matter waves 13. The velocity of sound in a vacuum is
B. Electromagnetic waves A. 332 ms-1
C. Carrier waves B. 320 ms-1
D. Mechanical waves C. Zero
D. 224 ms-1
3. The distance between any two consecutive crests or troughs
is called 14. Increase in velocity of sound in the air for 1°C rise in
A. Frequency temperature is
B. Period A. 1.61 ms-1
C. Wavelength B. 61.0 ms-1
D. Phase difference C. 0.61 ms-1
D. 2.00 ms-1
4. When two identical travelling waves are superimposed, the
velocity of the resultant wave 15. The velocity of sound is greatest in
A. Decreases A. Water
B. Increases B. Air
C. Remains unchanged C. Copper
D. Becomes zero D. Ammonia

5. In vibrating cord, the points where the amplitude is 16. The normal ear is the most sensitive in the frequency
maximum, are called range
A. Antinodes A. 20000 to 30000 hertz
B. Nodes B. 10 to 20 hertz
C. Troughs C. 2000 to 4000 hertz
D. Crests D. 6000 to 8000 hertz

6. The distance between two consecutive nodes is 17. Ultrasonic have

A. λ/2 A. Frequency in the audible range
B. λ/4 B. Frequency is greater than 20 kHz
C. λ C. Frequency lower than 20 Hz
D. 2λ D. All of above

7. The distance between a consecutive node and antinode is 18. The periodic alternation of sound between a maximum
A. λ and minimum loudness is called
B. λ/2 A. Silence zone
C. 2λ B. Interference
D. λ/4 C. Beats
D. Resonance
8. If stretching force T of wire increases, then its frequency
A. Decreases 19. The number of beats produced per second is equal to
B. Increases A. The sum of the frequencies of two tuning forks
C. Remains the same B. The difference of the frequencies of two tuning forks
D. None of above C. The ratio of the frequencies of two tuning forks
D. The frequency of either of the two tuning forks
9. A stationary wave is set up in the air column of a closed
pipe. At the closes end of the pipe 20. Beats are the results of
A. Always a node is formed A. Diffraction of sound waves
B. Always an antinode is formed B. Constructive and destructive interference
C. Neither node nor antinode is formed C. Polarization
D. Sometimes a node and sometimes an antinode is formed D. Destructive interference

10. It is possible to distinguish between transverse and 21. Silence zone takes place due to
longitudinal waves form the property of A. Constructive interference
A. Refraction B. Destructive interference
B. Polarization C. Beats
C. Interference D. Resonance
D. Diffraction
22. Doppler effect applies to
A. Soundwave only
B. Light wave only 33. The speed of stationary waves in a stretched string is
C. Both sound and light waves independent of
D. Neither sound nor light wave A. Number of loops
B. The tension in the string
23. When the source of sound moves away from a stationary C. Point where a string is plucked
listener then _________ occurs. D. Both A and C
A. An apparent increase in frequency
B. An apparent decrease in frequency 34. The fundamental frequency of stationary waves in open
C. An apparent decrease in wavelength pipe is ________ times the frequency in a closed pipe.
D. No apparent change in frequency A. One
B. Two
24. Which one is the correct relation for a fundamental C. Four-time
frequency of open and closed pipe? D. None of these
A. f open = 2f closed
B. f closed = 2f open 35. Which phenomena can be applied to estimate the velocity
C. f open = f closed of a star with respect to the earth
D. f open = 1/f closed A. Doppler’s effect
B. Interference of waves
25. In open organ pipe C. Beats phenomena
A. Only even harmonics are present D. All of these
B. Only odd harmonics are present
C. Both even and odd harmonics are present 36. Velocity of sound waves in vacuum
D. Selected harmonics are present A. 300 m/s
B. 320 m/s
26. Which one is the correct relation? C. 330 m/s
A. V Newton = V Laplace D. None
B. V Newton = γV Laplace
C. V Newton =√γ V Laplace 37. The waves moving from sitar to listener in air are
D. V Laplace = √γ V Newton A. Longitudinal progressive
B. Longitudinal stationary
27. Waves produced at the surface of water by a pencil C. Transverse progressive
executing vibrating motion if held vertically at a frequency of D. Transverse stationary
50Hz are
A. Longitudinal 38. The speed of sound wave is correctly formulated by
B. Transverse A. Newton
C. Periodic B. Pascal
D. Both A and C C. Newton & Laplace
D. Laplace
28. Newton estimated the speed of sound
A. 281m/sec 39. Period of simple pendulum depends on
B. 333m/sec A. Mass
C. 340m/sec B. Length
D. All of the above C. Both
D. Total energy
29. Laplace found that the alternate compressions and
rarefactions produced in sound waves follow 40. Speed of sound is greater in
A. Isothermal law A. Solids
B. Adiabatic law B. Liquids
C. Isochoric law C. Gases
D. All of the above D. All have same speed of sound

30. For destructive interference of sound waves the path

difference between two interfering sounds should be
A. nπ
B. (n+1/2)π
C. Some time n? and sometimes (n+1/2)π
D. None of these

31. The speed of sound in hydrogen is __________ time than

that in oxygen
A. Two times
B. Three times
C. Four times
D. Six times

32. The beats frequency (sensible) for a human car is

A. 42Hz
B. 7 Hz
C. 256Hz
D. 262Hz