Sound Worksheet-3

Sound Worksheet-3

 

  1. If the speed of a wave is 340 m/s and its frequency is 1700 Hz, then λ for this wave in cm will be:

A. 2                     B. 0.2                  C. 20                   D. 200

 

  1. A musical instrument is producing a continuous note. This note cannot be heard by a person having a normal hearing range. This note must then be passing through :

A. water             B. wax                C. vacuum         D. empty vessel

 

  1. Which one of the following does not consist of transverse waves ?

A. light emitted by a CFL

B. TV signals from a satellite

C. ripples on the surface of a pond

D. musical notes of an orchestra

 

  1. Sound travels in air :

A. if particles of medium travel from one place to another

B. if there is no moisture in the atmosphere

C. if disturbance moves

D. if both, particles as well as disturbance move from one place to another

 

  1. In the sound wave produced by a vibrating tuning fork shown in the diagram, half the wavelength is represented by :

A. AB                  B. BD                  C. DE                  D. AE

 

  1. The maximum speed of vibrations which produce audible sound will be in :

A. dry air                                        B. sea water

C. ground glass                             D. human blood

 

  1. The sound waves travel fastest:

A. in solids                                     B. in liquids

C. in gases                                      D. in vacuum

 

  1. The speeds of sound in four different media are given below. Which of the following is the most likely speed in m/s with which the two under water whales in a sea talk to each other when separated by a large distance?

A. 340                B. 5170               C. 1280              D. 1530

 

  1. When the pitch of note produced by a harmonium is lowered, then the wavelength of the note :

A. decreases

B. first decreases and then increases

C. increases

D. remains the same

 

  1. The velocities of sound waves in four media P, Q, R and S are 18,000 km/h, 900 km/h, 0 km/h, and 1200 km/h respectively. Which medium could be a liquid substance?

A. P                     B. Q                     C. R                     D. S

 

Answer Key:

  1. C

Explanation: V = f × λ     

34000 Cm/sec= 1700 × λ

λ = 20 cm

  1. C

  2. D

  3. C

  4. B

  5. C

  6. A

  7. D

  8. C

  9. D