Important MCQ on Sound Waves for competitive exams like SSC JKSSB
JKPSC RRB SSC-CGL
1. What type of waves are Sound Waves?
A. Latitudinal waves
B. Longitudinal waves
C. Latitudinal mechanical waves
D. Longitudinal waves
Sound Waves are longitudinal mechanical waves.
2. Which of the following is/ are not applications of Ultrasonic Waves?
(a) For measuring the depth of Sea.
(b) In sterilizing of a liquid.
(c) In Ultrasonography
(d) In sterilizing a needle.
A. Both (a) and (b) Only (b)
B. Only (d)
C. Both (c) and (d)
D. Only (b)
Applications of Ultrasonic Waves are: sending signals, for measuring the depth of sea, for cleaning cloths, aeroplanes, machinery parts of clocks, for removing lamp-shoot from the chimney of factories, in sterilizing of liquid and in Ultrasonography.
3. What is the speed of sound in air?
A. 330 m/s
B. 332 m/s
C. 334 m/s
D. 336 m/s
The speed of Sound in Air (00C) is 332 m/s and in Air (200C) is 343 m/s.
4. What will be the effect of temperature on speed of sound?
A. The speed of sound decreases with the increases of temperature of the medium.
B. The speed of sound decreases with the decrease of temperature of the medium.
C. The speed of sound increases with the decrease of temperature of the medium.
D. The speed of sound increases with the increase of temperature of the medium.
5. Name the characteristic of the sound which distinguishes a sharp
sound from a grave or dull sound?
Pitch is that characteristic of sound which distinguishes a sharp or shrill sound from a grave or dull sound. It depends upon frequency. Higher the frequency higher will be the pitch and shriller will be the sound and vice versa.
6. Due to which phenomena sound is heard at longer distances in nights than in day?
C. Interference of sound
D. Diffraction of sound
Due to refraction, sound is heard at longer distances in nights than in day.
7. When a motor boat in a sea travels faster than sound, then waves just like shock-waves are produced on the surface of water. These waves are called ..............
A. Shock waves
B. Doppler’s waves
C. Refracted waves
D. Bow waves
When a motor boat in a sea travels faster than sound, then waves just like shock-waves are produced on the surface of water. These waves are called bow waves.
8. What is Intensity of Sound?
A. It is inversely proportional to the square of the distance of point from the source.
B. It is directly proportional to the square of amplitude of vibration, square of frequency and density of the medium.
C. Both A and B
D. Neither A nor B
Intensity of any sound at any point in space is the amount of energy passing normally per unit area held around that point per unit time. S.I unit of intensity is watt/m2.
9. What is the unit of loudness?
D. All of the above
The sensation of a sound perceived in a ear is measured by another term called loudness which depends on intensity of sound and sensitiveness of the ear. Unit of loudness is bel. A practical unit of loudness is decibel (dB) which is 1/10th of bel. Another unit of loudness is phon.
10. Which of the following statement is or are correct about longitudinal mechanical waves?
A. The longitudinal mechanical waves which lie in the frequency range 20 Hz to 20000 Hz are called audible or sound waves.
B. The longitudinal mechanical waves having frequencies less than 20 Hz are called infrasonic.
C. The longitudinal mechanical waves having frequencies greater than 20,000 Hz are called ultrasonic waves.
D. All of the above are correct
Sound or Audible waves are sensitive to human ear and are generated by the vibrating bodies like tuning fork, vocal cords etc. Infrasonic waves are produced by sources of bigger size such as earth quakes, volcanic eruptions, ocean waves etc. Human ear cannot detect Ultrasonic waves. But dog, cat, bat etc can detect these waves. Bat not only detect but also produce ultrasonic waves.