THESE NOTES ARE PREPARED ACCORDING TO JKBOSE SYLLABI IN SIMPLIFIED AND CONCISE PATTERN
Textual Questions
Q. Choose the correct answer:
1. Sound can travel through:
A. Gases only B. Solids only
C. Liquids only D. Solids, Liquids and Gases
Ans: D. Solids, Liquids and Gases
2. Which of the following voices is likely to have minimum frequency :
A. Baby Girl B. Baby Boy
C. A Man D. A Woman
Ans: C. A Man
Q. State whether True or False:
a. Sound cannot travel in Vaccum:
1. Sound can travel through:
A. Gases only B. Solids only
C. Liquids only D. Solids, Liquids and Gases
Ans: D. Solids, Liquids and Gases
2. Which of the following voices is likely to have minimum frequency :
A. Baby Girl B. Baby Boy
C. A Man D. A Woman
Ans: C. A Man
Q. State whether True or False:
a. Sound cannot travel in Vaccum:
Ans: True
b. The number of oscillations per second of a vibrating object is called its Time period:
b. The number of oscillations per second of a vibrating object is called its Time period:
Ans: False
c. If the amplitude of sound is large, sound is feeble:
Ans: False
d. For human Ear, the audible range is 20 Hz to 20000 Hz:
Ans: True
e. The lower the frequency of vibration, the higher is the pitch:
e. The lower the frequency of vibration, the higher is the pitch:
Ans: False
f. Unwanted or unpleasant sound is termed as Music:
f. Unwanted or unpleasant sound is termed as Music:
Ans: False
g. Noise Pollution may cause partial hearing Impairment:
g. Noise Pollution may cause partial hearing Impairment:
Ans: True
Q. Fill in the blanks:
A. Time taken by object to complete one oscillation is called TIME PERIOD
B. Loudness is determined by .AMPLITUDE... of vibration
C. The unit of frequency is .HERTZ...
E. Unwanted sound is called . .....Noise.....
F. Shrillness of sound is determined by ..FREQUENCY..... of vibration.
Q. A Pendulum oscillates 40 times in 4 seconds. Find its Time period and Frequency.
Ans: Number of oscillations = 40
Time = 4 sec
Time Period = Time Taken
Oscillations
Time Period = 4/40
Time Period = 0.1 Seconds.
Frequency = Oscillations
Time
Frequency = 40 / 4
Frequency = 10 Hertz.
Q. The sound of mosquito is produced when it vibrates its wings at average rate of 500 vibrations per second. What is the time period of the vibration?
Ans:
Time Period = Time Taken
Oscillations
Time Period = 1 / 500
Time Period = 0.002 seconds.
Q. Fill in the blanks:
A. Time taken by object to complete one oscillation is called TIME PERIOD
B. Loudness is determined by .AMPLITUDE... of vibration
C. The unit of frequency is .HERTZ...
E. Unwanted sound is called . .....Noise.....
F. Shrillness of sound is determined by ..FREQUENCY..... of vibration.
Q. A Pendulum oscillates 40 times in 4 seconds. Find its Time period and Frequency.
Ans: Number of oscillations = 40
Time = 4 sec
Time Period = Time Taken
Oscillations
Time Period = 4/40
Time Period = 0.1 Seconds.
Frequency = Oscillations
Time
Frequency = 40 / 4
Frequency = 10 Hertz.
Q. The sound of mosquito is produced when it vibrates its wings at average rate of 500 vibrations per second. What is the time period of the vibration?
Ans:
Time Period = Time Taken
Oscillations
Time Period = 1 / 500
Time Period = 0.002 seconds.
Q. Identify the part which vibrates to produce sound in following instruments:
A. Dholak B. Sitar C. Flute
Ans:
(A) Dholak: Dholak has membrane that vibrate to produce sound.
(B) Sitar: Sitar has strings which vibrate to produce sound.
(C) Flute: Clute has air column inside which vibrates to produce sound.
Q. What is difference between Noise and Music. Can Music become Noise sometimes.
Ans: The sound which is unpleasant for our ears is called noise.
A. Dholak B. Sitar C. Flute
Ans:
(A) Dholak: Dholak has membrane that vibrate to produce sound.
(B) Sitar: Sitar has strings which vibrate to produce sound.
(C) Flute: Clute has air column inside which vibrates to produce sound.
Q. What is difference between Noise and Music. Can Music become Noise sometimes.
Ans: The sound which is unpleasant for our ears is called noise.
Music is the sound which is pleasant for our ears and has soothing affect.
Music can become noise when it crosses the bearable range of sound for our ears.
Q. List the sources of Noise pollution in your sorroundings.
Ans: Sources of noise pollution in our sorroundings are:
Firecrackers, Loudspeakers, Vehicles, Construction, Home and Kitchen appliances, Aeroplanes etc.
Q. Explain in what way noise pollution is harmful to humans?
Ans: Noise pollution is harmful to humans in many ways;
i) Noise pollution can cause temporary or permanent hearing loss.
(ii) Noise pollution can cause many health issues
(iii) It disturbs sleep etc.
Q. Your parents are going to buy a house. They have been offered one on the road side and another three lanes away from roadside. Which house would you suggest your parents should buy? Explain your answer.
Ans: I would suggest my parents to buy a house which is three lanes away from roadside.
There would be very less air and noise pollution than the house on roadside.
Q. Sketch the Larynx and explain its functions in your own words?
Ans:
Larynx is the voice box of human beings. There are two vocal cords attached to it.
The larynx helps in production of sound by vibration of vocal cords.
Q. Lightning and thunder take place in the sky at the same time and at the same distance from us. Lightning is seen earlier and thunder is heard later. Can you explain?
Ans: Lightning is a light energy where as thunder is a sound energy. Althought both take place at same time but Light travels faster than sound, therefore lightning is seen earlier than thunder.
The larynx helps in production of sound by vibration of vocal cords.
Q. Lightning and thunder take place in the sky at the same time and at the same distance from us. Lightning is seen earlier and thunder is heard later. Can you explain?
Ans: Lightning is a light energy where as thunder is a sound energy. Althought both take place at same time but Light travels faster than sound, therefore lightning is seen earlier than thunder.
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Open air Painting competition being held at H/S Amad.
