Match the coloumns: 1) Sound is produced when objects a) reflected 2) Sound can be b) vibrate 3) Echo is a type of c) hertz 4) Human ear can hear the sound waves of frequency d) time period 5) Some animals can hear the sounds of frequency e) 20 - 20 , 000 Hz 6) Frequency is the inverse of f) higher than 20 , 000 Hz 7) The unit of frequency is g) reflected sound

The correct match of coloumns: 1) Sound is produced when objects b) vibrate 2) Sound can be a) reflected 3) Echo is a type of g) reflected sound 4) Human ear can hear the sound waves of frequency e) 20 - 20 , 000 Hz 5) Some animals can hear the sounds of frequency f) higher than 20 , 000 Hz 6) Frequency is the inverse of d) time-period 7) The unit of frequency is c) hertz A vibrating body is a source of sound. When the reflected sound comes back after a time interval of 0.1 seconds then, an echo is heard clearly. The audible range of humans is 20 - 20 , 000 Hz but, some animals can hear beyond this range. Frequency can be expressed in units of s - 1 or hertz.

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Lakhmir Singh's Science Physics>Chapter 6 - Sound>EXERCISES>Q 6

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The pitch of a sound is directly proportional to its frequency.

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Important Questions on Sound

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Lakhmir Singh's Science Physics>Chapter 6 - Sound>EXERCISES>Q 7

A bat produces ultrasonic sound during screaming.

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Lakhmir Singh's Science Physics>Chapter 6 - Sound>EXERCISES>Q 8

Noise is produced by the regular vibrations.

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Lakhmir Singh's Science Physics>Chapter 6 - Sound>EXERCISES>Q 9

Carpets are put on the floor to reflect sound and reduce reverberations.

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Lakhmir Singh's Science Physics>Chapter 6 - Sound>EXERCISES>Q 10

We can hear more clearly in a room having curtains because curtains are good reflectors of sound.

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Lakhmir Singh's Science Physics>Chapter 6 - Sound>EXERCISES>Q 1

Match the coloumns:

1) Sound is produced when objects	a) reflected
2) Sound can be	b) vibrate
3) Echo is a type of	c) hertz
4) Human ear can hear the sound waves of frequency	d) time period
5) Some animals can hear the sounds of frequency	e) $20 - 20, 000 Hz$
6) Frequency is the inverse of	f) higher than $20, 000 Hz$
7) The unit of frequency is	g) reflected sound