Science - Sound
Exam Duration: 45 Mins Total Questions : 30
A mechanical wave travels in a medium. Which of the following quantities is transferred from one place to another with the wave?
- (a)
Mass
- (b)
Speed
- (c)
Density
- (d)
Energy
On a slinky, which of the following is produced?
- (a)
A longitudinal wave but not a transverse wave
- (b)
A transverse wave but not a longitudinal wave
- (c)
A longitudinal wave as well as a transverse wave
- (d)
Neither a longitudinal nor a transverse wave
In which of the following media can nonmechanical waves travel
- (a)
In vacuum as well as in a medium
- (b)
In vacuum but not in a medium
- (c)
In a medium but not in vacuum
- (d)
Neither in a medium nor in vacuum
What is the distance between a crest and a trough in a wave
- (a)
入
- (b)
\(\frac { 入 }{ 2 } \)
- (c)
\(\frac { 入 }{ 4 } \)
- (d)
B入
A wave source produces 20 crests and 20 troughs in 0.2 s. Find the frequency of the wave.
- (a)
200 Hz
- (b)
500 Hz
- (c)
100 Hz
- (d)
300 Hz
The time period of a periodic wave is 0.02 seconds. At a particular position there is a crest at t = o.At what value of't' will the next trough appear at this position
- (a)
0.05 s
- (b)
0.01 s
- (c)
0.15 s
- (d)
0.25 s
A longitudinal wave travels from east to west in air. In which direction do the particles of air move?
- (a)
East to west
- (b)
East to west and north to south
- (c)
North to south
- (d)
South to north
A long spring is fixed at one end. A person holding the other end compresses the spring with a jerk. The compression travels along the length of the spring. Which kind of wave is travelled along the length of the spring?
- (a)
Electromagnetic waves
- (b)
Transverse waves
- (c)
Longitudinal waves
- (d)
Both (A) and (e)
What is the minimum distance between two crests called?
- (a)
Wavelength
- (b)
Amplitude
- (c)
Displacement
- (d)
Wave pulse
If the density of air at a point through which a sound wave is passing maximum at an instant, what will be the pressure at that point?
- (a)
Minimum
- (b)
Equal to the density of air
- (c)
Equal to the atmospheric pressure
- (d)
Maximum
An object is moving at a speed greater than that of sound. What is the speed with which the object is moving?
- (a)
Ultrasonic speed
- (b)
Sonic speed
- (c)
Infrasonic speed
- (d)
Supersonic speed
A sound wave has a frequency of 1000Hz and a wavelength of 34 cm. How long will it take to travel 1 km?
- (a)
3.20 s
- (b)
2.94 s
- (c)
5.94 s
- (d)
3.10 s
Ultrasonic waves are used for detecting objects under water. What is the technique/device used for this?
- (a)
Ultrasonography
- (b)
Echocardiography
- (c)
Phakoemulsification
- (d)
Sonar
A worker lives at a distance of 1.32 km from the factory. If the speed of sound in air is 330 m S-I, how long will the sound of factory siren take to reach the worker?
- (a)
1s
- (b)
2s
- (c)
3s
- (d)
4s
A boy stands facing a high wall at a distance of 85 m from it and then blows a whistle. Calculate the time interval when he hears an echo. (Speed of sound = 340 ms-1).
- (a)
1 s
- (b)
2 s
- (c)
0.5 s
- (d)
3 s
Longitudinal waves can not travel through
- (a)
vacuum
- (b)
solids
- (c)
liquids
- (d)
gases
A bomb explodes on the moon. How long will it take for the sound to reach the earth?
- (a)
10 seconds
- (b)
1000 seconds
- (c)
1 day
- (d)
It does not reach the earth
A pendulum vibrates with a time period of 1 second. What kind of sound is produced by it?
- (a)
Supersonic
- (b)
Audible
- (c)
Infrasonic
- (d)
Ultrasonic
When sound waves travel from one medium to another, which of the following physical quantities does NOT alter?
- (a)
Amplitude
- (b)
Velocity
- (c)
Frequency
- (d)
Intensity
Flash and thunder are produced simultaneously. But the thunder is heard a few seconds after the flash is seen. Why?
- (a)
The speed of sound is greater than the speed of light.
- (b)
The speed of sound is equal to the speed of light.
- (c)
The speed of light is greater than the speed of sound.
- (d)
The speed of light is less than the speed of sound
Match the entries in Column I with those in Column II correctly
Column-I |
Column-II |
||
a | Microphone | 1 | Wind energy into mechanical energy |
b | Speaker | 2 | Mechanical energy into sound energy |
c | Reeds of a harmonium |
3 | Electrical energy into sound energy |
d | Sails of a ship | 4 | Sound energy into electrical energy |
- (a)
a-4, b-3, c-1, d-2
- (b)
a-1, b-2, c-3, d-4
- (c)
a-4, b-2, c-3, d-1
- (d)
a-4, b-3, c-2, d-1
How are bats able to fly in the dark?
- (a)
They produce infrasonic waves.
- (b)
They can hear ultrasonic sounds.
- (c)
They produce infrared waves.
- (d)
They can hear infrared waves
What types of waves are seismic waves?
- (a)
Non-mechanical waves
- (b)
Elastic waves
- (c)
Mechanical waves
- (d)
Electromagnetic waves
Arrange the following media in ascending order of the speed of sound in them?
- (a)
(iii), (ii), (i)
- (b)
(i), (iii), (ii)
- (c)
(iii), (i), (ii)
- (d)
(ii), (i), (iii)
Why do distant sounds such as those of traffic and loudspeakers become louder during the night time than during the day time?
- (a)
Due to the reflection of sound waves
- (b)
Due to the refraction of sound waves
- (c)
Due to the absence of other sounds
- (d)
Due to a clear perception of hearing
Which of the following is NOT an application of ultrasound waves?
- (a)
- (b)
- (c)
- (d)
An ultrasonic wave is sent from a ship towards the bottom of the sea.It is found that the time interval between the sending and receiving of wave is 1.6 s.What is the depth of the sea,if the velocity of sound in sea water is 1400 m s-1?
- (a)
1120 m
- (b)
60 m
- (c)
1400 m
- (d)
112 m
A tuning fork of frequency 420 Hz completes 70 vibrations. Find the distance travelled by sound in air. (v = 360 m s-1)
- (a)
20 m
- (b)
50 m
- (c)
60 m
- (d)
80 m
A wave offrequency 500 Hz has avelocity of 360 m s-1. Calculate the distance between two points that are 60° out of phase
- (a)
12 cm
- (b)
18 cm
- (c)
24 cm
- (d)
32 cm
The velocity of sound in air
- (a)
decreases with an increase in temperature.
- (b)
increases with a decrease in temperature
- (c)
decreases with a decrease in temperature
- (d)
does not depend on temperature