|
When the wire of a guitar is plucked
|
|
3
|
3507
|
February 2, 2019
|
|
Sketch larynx and explain its function in your own words
|
|
1
|
13921
|
March 22, 2018
|
|
What is the difference between noise and music? Can music become noise sometimes?
|
|
1
|
569
|
March 22, 2018
|
|
Suggest four measures to limit noise pollution in your locality
|
|
1
|
412
|
March 22, 2018
|
|
How is sound produced and how is it transmitted and heard by us?
|
|
1
|
2908
|
March 22, 2018
|
|
List sources of noise pollution in your surroundings
|
|
1
|
6542
|
March 22, 2018
|
|
Your parents are going to buy a house
|
|
1
|
376
|
March 22, 2018
|
|
Explain in what way noise pollution is harmful to humans
|
|
1
|
850
|
March 22, 2018
|
|
We have a stringed musical instrument. The string is plucked in the middle first with a force of greater magnitude and then with a force of smaller magnitude
|
|
1
|
1502
|
March 22, 2018
|
|
An alarm bell is kept inside a vessel as shown in the figure below
|
|
1
|
1807
|
March 22, 2018
|
|
Identify the part which vibrates to produce sound in the following instruments
|
|
1
|
431
|
March 22, 2018
|
|
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?
|
|
1
|
968
|
March 22, 2018
|
|
A pendulum oscillates 40 times in 4 seconds. Find its time period and frequency
|
|
1
|
754
|
March 22, 2018
|
|
Two astronauts are floating close to each other in space. Can they talk to each other without using any special device? Give reasons
|
|
1
|
1248
|
March 22, 2018
|
|
Suppose a stick is struck against a frying pan in vacuum. Will the frying pan vibrate?
|
|
1
|
1140
|
March 22, 2018
|
|
We have learnt that vibration is necessary for producing sound. Explain why the sound produced by every vibrating body cannot be heard by us
|
|
1
|
534
|
March 22, 2018
|
|
A simple pendulum makes 10 oscillations in 20 seconds. What is the time period and frequency of its oscillation?
|
|
1
|
585
|
March 22, 2018
|
|
Figure shows a loudspeaker cone oscillating to produce sound waves:
|
|
1
|
959
|
March 21, 2018
|
|
Represent graphically any two separate diagrams in each case:
|
|
1
|
340
|
March 21, 2018
|
|
What is meant by reflection of sound?
|
|
1
|
400
|
March 21, 2018
|
|
Give reasons for the following: The reverberation time of a hall used for speeches should be very short
|
|
1
|
1806
|
March 21, 2018
|
|
State an approximate value for the speed of sound in air
|
|
1
|
711
|
March 21, 2018
|
|
A girl is sitting in the middle of a park of dimension 12 m X 12 m
|
|
1
|
3717
|
March 21, 2018
|
|
In the graphs given below representing the human voice, which of the two graphs or is likely to be the male voice? Give reason for your answer
|
|
1
|
1138
|
March 21, 2018
|
|
What is a sound board?
|
|
1
|
2000
|
March 21, 2018
|
|
Write full form of acronym SONAR. Explain how the method of echo- ranging is used to determine the depth of sea
|
|
1
|
1780
|
March 21, 2018
|
|
Draw diagrams to represent soft sound and loud sound
|
|
1
|
1300
|
March 21, 2018
|
|
. Plot the following: A longitudinal wave in air on a density-distance graph. A transverse wave on a displacement-distance graph
|
|
1
|
1426
|
March 21, 2018
|
|
Which wave characteristics determine the loudness pitch of sound?
|
|
1
|
449
|
March 21, 2018
|
|
Prove that u=vλ, where the symbols have their usual meanings
|
|
1
|
1054
|
March 21, 2018
|
