Sound can travel through

1

(a)

gases only

(b)

solids only

(c)

liquids only

(d)

solids, liquids and gases

The hearing range of human ear is

1

(a)

20 Hz to 20 kHz

(b)

less than 20 Hz

(c)

more than 20 kHz

(d)

20 Hz to 25,000 Hz

The normal range of vocal cords in women is

1

(a)

20 mm

(b)

10 mm

(c)

15 mm

(d)

40 mm

Vibrations in a body produce

1

(a)

sound

(b)

pressure

(c)

density

(d)

current

1 Hz is equal to

1

(a)

1 vibration per minute

(b)

10 vibrations per minute

(c)

60 vibrations per minute

(d)

600 vibrations per minute

Sound which is pleasing to our ears is called..............

1

(a)

music

The loudness of sound is determined by the...........of vibration

1

(a)

amplitude

The time period is measured in............

1

(a)

second

The other name of human voice box is............

1

(a)

larynx

A person having partial hearing loss can hear properly by using a device called.......aid.

1

(a)

hearing

If the amplitude of vibration is large, sound is feeble.

1

(a) True

(b) False

For human ears, the audible range is 20 Hz to 20,000 Hz.

1

(a) False

(b) True

Lower the frequency of vibration, higher is the pitch.

1

(a) True

(b) False

Unwanted or unpleasant sound is termed as music

1

(a) True

(b) False

Noise pollution may cause partial deafness

1

(a) False

(b) True

Briefly, mention the experience when you touch a sound producing school bell?

2

(a)

Three different vibrating objects produce three types of sounds X, Y and Z. The sounds X and Y cannot be heard by a man having normal range of hearing but sound Z can be heard easily. The sound X can be heard by a bat whereas sound Y can be heard by a rhinoceros. What type of sounds are X, Y and Z?

2

(a)

A hearing aid that is attached to the ear helps people who suffer from hearing loss. What is the main function of the hearing aid?

2

(a)

Among water and steel, in which medium the sound wave will travel faster?

2

(a)

What is the similarity between pitch and frequency?

2

(a)

A stretched string on being set into vibration, produce the audible sound. Explain how.

3

(a)

Explain the process, how is sound produced in humans.

3

(a)

Explain the process, how bat sure ultrasonic waves to catch a prey

3

(a)

Explain how is the blind folded person able to guess which player is closest to her

3

(a)

Explain the reason for not hearing of the screams of a bat by us.

3

(a)

Explain in brief about eardrum. Also explain how does it play an important role in hearing.

5

(a)

Anjali's grandfather was talking to her about the quality of sound produced by different musical instruments. The instruments like sitar, harmonium, flute, etc., give us a pleasant sensation of hearing. The dholak on the other side creates a noise.
(a) Mention the name of the vibrating part of sitar.
(b) Briefly explain how the loudness is created by dholak.
(c) We hear a shrilling sound by flute. Explain why?
(d) Mention the values displayed by Anjali's grandfather

5

(a)