10th SCIENCE REFRESHER COURSE 7 Answer key

SOUND

10th SCIENCE REFRESHER COURSE 7 Answer key

EVALUATION ANSWERS -7

EVALUATION

I.  Choose the correct answer

1. Sound waves travel very fast in

a) Air

b) Metal           

c)  Vacuum

d) Liquids

2. The amplitude of the sound wave decides its

b) Pitch            c) Loudness

a) Speed

3. Find the odd one out.

d) Frequency

a) Harmonium             b)  Flute           c) Nadaswaram            d) Violin

4. Noise is produced by

.

a) Vibrations with high frequency                    b) Regular vibrations

c) Regular and Periodic vibrations d) Irregular and non-Periodic vibrations

5. The range of audible frequency for the human ear is

b)  20Hz to 2000Hz

a) 2Hz to 2000Hz

c)   20Hz to 20000Hz               d) 200Hz to 20000Hz

6. Which of the following are the characteristics of vibrations ?

iv) Loudness

d) i and iv

ii) Time Period           iii) Pitch

i) Frequency

a) i and ii

c) iii and iv

b) ii and iii

7. What king of musical instrument is a sitar?

a) String instrument

b) Percussion instrument

c) Wind instrument

d) None of these

8.  If amplitude and frequency of sound wave are increased, which of the following is true?

a. Loudness increases and pitch is higher

b. Loudness increases and pitch is unchanged

9. Which of the following may be caused by noise?

c. Loudness increases and pitch is lower

d. Loudness decreases and pitch is lower

a) Irritation

b) Stress           

c)  Nervousness           

d) All the above.

10. Sound travels in air _____________

a) if there is no moisture in the atmosphere.

b) if particles of medium travel from one place to another.

c) if both particles as well as disturbance move from one place to another.

d) if disturbance moves.

II.  Fill in the blanks

1. Sound is produced by _______.             vibration

2. The vibrations of a simple pendulum are also known as _______.             Waves

3.  Sound travels in the form of _______.             mechanical wave

4. High frequency sounds that cannot be heard by you are called _______. ultrasonic

5. Pitch of a sound depends on the _____     frquency     vibration.

6.  If the thickness of a vibrating string is increased, its pitch ______.           decrease

7.  Vibration of object produces _________ .

8.The speed of a wave is the distance travelled by it in a second