Sound: Model Test

                             OBJECTIVE
1.Light is a 
A. Transerve wave 
B. Longitudinal wave
C. Non-Mechanical wave 
D. Both A & C

2. A sound is produced by 
A. Vibration
B. Movement of Matter
C. When force is applied on the body
D. None of these

3. If a body produces a frequency of 344Hz and speed of the sound wave is 344m/s then find the wavelength of the wave-
A.688m
B.1m
C.172m
D.Depends on the amplitude

4. The maximum displacement between two consecutive crests and trough is
A. Amplitude
B. Frequency
C. Time Period
D. None of the above

5. Sound cannot travel through-
A. air
B. Water
C. Vacuum
D. Steel 

6. Sound travels in maximum speed in 

A. Solids
B. Liquids
C. Gases
D. Vacuum 

7. Average speed of Sound wave in air
A. 300m/s
B. 344m/s
C. 400m/s
D. 500m/s

8. Unit of wave length is 
A. m
B. m/s
C. mv
D. km

9. Time period and Frequency are
A. Directly proportional
B. Inversely proportional
C. Same
D. None of these

10. Unit of frequency is 
A. Hz
B. Hertz
C. Both
D. None 


Fill in the blanks with suitable words.
(a) Time taken by an object to complete one oscillation is called
................... .
(b) Loudness is determined by the .........................of vibration.
(c) The unit of frequency is..........................
(d) Unwanted sound is called ......................... .(e) Shrillness of a sound is determined by the ................. of vibration.

State True or False
(a) Sound cannot travel in vacuum. (T/F)
(b) The number of oscillations per second of a vibrating object is called
its time period. (T/F)
(c) If the amplitude of vibration is large, sound is feeble. (T/F)
(d) For human ears, the audible range is 20 Hz to 20,000 Hz. (T/F)
(e) The lower the frequency of vibration, the higher is the pitch. (T/F)
(f) Unwanted or unpleasant sound is termed as music. (T/F)
(g) Noise pollution may cause partial hearing impairment. (T/F)

          SUBJECTIVE

1.A pendulum oscillates 40 times in 4 seconds. Find its time period and
frequency.
2. The sound from a mosquito is produced when it vibrates its wings at an
average rate of 500 vibrations per second. What is the time period of the
vibration?
3. Identify the part which vibrates to produce sound in the following
instruments:
(a)  Dholak (b)  Sitar (c)  Flute
4. What is the difference between noise and music? Can music become noise
sometimes?
5. List sources of noise pollution in your surroundings.10. Explain in what way noise pollution is harmful to humans.