Class 9 Science Important Questions for Sound |physics

Short Answer Based questions

1. Arrange the speed of sound in Steel, water and air in ascending order?
2. What is the relation between frequency and time period of the wave?
3. Sound waves are transverse waves True or False?
4. Arrange the speed of these waves in air in descending order   a) light  b) Sound c) Supersonic aircraft?
5. What is an echo?
6. What are three characteristics of the sound
7. What is the audible  range of sound frequencies for human ear?
8. What is Reflection of sound?

Match the column

Column A (Frequency)	Column B (Sound range they fall)
5 Hz	Audible range
25000 Hz	Infrasonic range
25 Hz	Ultrasonic range
250 Hz
10 Hz
120000 Hz

Match the column

Column A	Column B
The maximum disturbance caused by the wave	wavelength
The distance travelled by a wave per second	frequency
The no of complete vibrations per sec	Velocity
The distance between one crest of wave and next one	Amplitude
When we change a feeble sound to loud sound, we increase its	Time period
When we change the pitch, what is getting changed

Table type question

Sound velocity	Frequency	Wavelength	Time period	Audible/Ultrasonic/Infrasonic
330 m/s	550Hz	?	?	?
	500hz	68m	?	?
343.4m/s	?	1.7 cm	?	?

Fill in the blanks
1)Sound waves   ……  travel in vacuum
2)The speed of sound depends on   ………….  And  …………
3)The soft and porous materials are bad  ………. Of sound
4)The speed of the highly penetrating ultrasonic waves are   …………………..  those of audible sound waves
5) The ……….. sound are produced before the main shock wave of earth quake
Crossword Puzzle
Across

4. It is used break kidney stones into fine grains

7. The unit of frequency

8. The loudness of the sound depends on this

9. Medical instrument used by the doctors for listening to heartbeats

10. It is the region of low pressure in longitudinal wave

Down

1. Apparatus used to find the depth of the sea

2. It converts sound wave frequency into electrical impulses

3. A vibrating simple pendulum produces this type of sound

5. It is the sensation of a frequency

6. Elevation in a transverse wave

Solution
Fill in the blank solution

1. Do not
2. Nature of the material ,temperature
3. Reflectors
4. Same
5. infrasonic

Crossword Solution
Across
Ultrasound,Hertz, Amplitude, Stethoscope, rarefaction
Down
Sonar, Cochlea, infrasonic, Pitch, crest




Class 9 Maths Class 9 Science