CBSE Class 8 Science Chapter 10 Sound Question And Answers

CBSE Class 8 Science Chapter 10 Sound Fill In The Blanks

Question 1. Sound is produced by__________ objects.
Answer: Vibrating

Question 2. The other name of human voice box is__________
Answer: Larynx

Question 3. Sound can travel in and __________
Answer: Solids, liquids, gases

Read And Learn More CBSE Class 8 Science Question And Answers

Question 4. The loudness of normal breathing of humans is__________ dB.
Answer: 10

Question 5. Vibration is repeated__________ and motion.
Answer: To, From

” Cbse Class 8 Science Chapter 10 Question And Answers “

Question 6. A tight membrane vibrates at a much__________ frequency than a loose one.
Answer: Higher

Question 7. Sound which is pleasing to our ears is called__________
Answer: Music

Question 8. A person having partial hearing loss can hear properly by using a device called__________ aid.
Answer: Hearing

Question 9. The speed of sound in air is__________
Answer: 344m/s

Question 10. Muscles attached to the vocal cords can make the cords ___________or__________
Answer: Tight, loose

” Sound Question And Answers Class 8 “

Question 11. The pitch of the sound depends on the_____________
Answer: Frequency

Question 12. The time taken by an object to complete one oscillation is called
Answer: Period

Question 13. The amount of vibration determines loudness.
Answer: Amplitude

Question 14. The unit of frequency is
Answer: Hertz

Question 15. Unwanted sound is called
Answer: Noise

Question 16. The frequency of vibration determines the Shrillness of a sound.
Answer: Frequency 

” Vibrating Objects Produce Sound “

CBSE Class 8 Science Chapter 10 Sound True Or False

Question 1. The intensity of the sound depends on the frequency of the wave.
Answer: True

Question 2. In human beings, the vibration of the vocal cords produces sound.
Answer: True

Question 3. The higher the amplitude of vibration, the lower the pitch.
Answer: False

Question 4. Regular vibrations produce musical sounds.
Answer: True

Question 5. Shriller sound has a higher frequency.
Answer: True

” Human Larynx And Vocal Cords “

Question 6. Plantation along the roadside can reduce noise pollution.
Answer: True

Question 7. Man cannot hear the sound of bats.
Answer: True

Question 7. The speed of sound is more than the speed of light.
Answer: False

Question 8. The sound travels fastest in solids.
Answer: True

Question 9. The sound waves produced by the bats are infrasonic.
Answer: False

Question 10. Sound cannot travel in a vacuum.
Answer: True

” Amplitude And Frequency Of Sound “

Question 11. The number of oscillations per second of a vibrating object is called its period.
Answer: False; The number of oscillations per second of a vibrating object is called frequency.

Question 12. If the amplitude of vibration is large, the sound is feeble.
Answer: False; Amplitude of vibration is directly proportional to the loudness of sound.

Question 13. For human ears, the audible range is 20 Hz to 20000 Hz.
Answer: True

Question 14. The lower the frequency of vibration, the higher the pitch.
Answer: False; The lower the frequency of vibration, the lower the pitch.

Question 15. Unwanted or unpleasant sound is termed as music.
Answer: False; Unwanted or unpleasant sound is termed as noise.

Question  16. Noise pollution may cause partial hearing impairment.
Answer: True

” Audible Range Of Human Ears “

CBSE Class 8 Science Chapter 10 Sound Match The Columns

Answer: 1-3, 2-3,3-1,4-5,5-4

CBSE Class 8 Science Chapter 10 Sound

The following questions consist of two statements- Assertion (A) and Reason (R). Answer these questions by selecting the appropriate options given below.

1. Both A and R are true, and R is the correct explanation of A.
2. Both A and R are true, but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false, but R is true.

Question 10.

Assertion (A) Sound travels more slowly through liquid than.
Reson (R) Thu moloculon In farther from onch other.

Answer: 1. Both A and R are true, and R is the correct explanation of A.

Question 11.

Assertion (A): The sound of women is shriller than that of men. Ronson (R) The pitch of the sound depends on the frequency of the sound.
Answer: 2. Both A and R are true, but R is not the correct explanation of A.

” Noise Pollution Causes And Effects “

The following questions consist of two statementsAssertion (A) and Reason (R). Answer these questions by selecting the appropriate option given below

1. Both A and R are true, and R is the correct explanation of A.
2. Both A and R are true, but R is not the correct explanation of A.
3. A is true, but R is false.
4. A is false, but R is true.

Question 1. Assertion (A) Astronauts in space can hear each other. Reason (R) Loud sounds have high amplitude.
Answer: 4. A is false because sound needs a medium to travel, but there is no medium in space. R is correct. Hence, the correct option is (d).

Question 2. Assertion (A) Tabla, sitar, flute, and harmonium are musical instruments. Reason (R) Sound is produced by vibrations in musical instruments.
Answer: Both A and R are correct because, without vibration, sound cannot be produced. Hence, the correct option is (a).

” Characteristics Of Sound Waves “

Question 3. Assertion (A) Frequency is measured in hertz (Hz). Reason (R) Lower the frequency, the higher the pitch of
The sound.
Answer: R is false because for higher frequency pitch of the sound is higher. Hence, the correct option is (c).

Question 4. Assertion (A) Human beings cannot hear sounds less than 20 Hz. Reason (R)The  Audible range of humans is 20 Hz to 20 KHz.
Answer: The audible range of sound for human beings is indeed from 20 Hz and 20 kHz. So, both A and R are correct, and R is the correct explanation. Hence, the correct option is (a).