WORK SHEET: SOUND
CLASS IX
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Multiple Choice Questions (1 Mark Each)
1. Children under the age of 5 can hear upto
a. 25 Hz b. 25k Hz c. 20 Hz d. 25 kHz
2. A tuning fork produces a sound wave of frequency 250 Hz. What will
happen if its frequency is doubled?
a) Pitch decreases b) Loudness increases c) Pitch increases d) Speed double
3. If the frequency of a sound wave is 500 Hz and its wavelength is 0.66 m,
what is the speed of sound?
a) 330 m/s b) 660 m/s c) 250 m/s d) 132 m/s
Assertion Reason Type Questions (1 mark each)
Directions: In each of the following questions, a statement of Assertion is given, and a
corresponding statement of Reason is given just below it. Of the statements, given
below, mark the correct answer as:
(a) Both assertion and reason are true, and reason is the correct explanation of
assertion.
(b) Both assertion and reason are true, but reason is not the correct explanation of
assertion.
(c) Assertion is true, but reason is false.
(d) Assertion is false, but reason is true
4. Assertion (A):Infrasonic sounds are inaudible to humans.
Reason (R): Human ears can detect frequencies between 20 Hz and 20,000 Hz.
5. Assertion (A): Echo is heard when the reflected sound reaches the listener
after 0.1 seconds.
Reason (R): The minimum distance for an echo to be heard is 17.2 m at room
temperature.
6. Why can you hear the sound of a train approaching through the rails earlier than
through air?
7. A) What is SONAR?
B) Find the frequency of a wave whose time period is 0.002 second
8. Read the given passage carefully and give the answer of the following questions:
(1x5)
Two friends Shefali and Anuj make a toy
telephone by joining two plastic cups
through a long string. They both stand
apart. Anuj speaks softly into one cup and
Shefali hears by putting her ear in the other
cup. Now, Shefali speaks and Anuj listens.
CLASS IX
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Multiple Choice Questions (1 Mark Each)
1. Children under the age of 5 can hear upto
a. 25 Hz b. 25k Hz c. 20 Hz d. 25 kHz
2. A tuning fork produces a sound wave of frequency 250 Hz. What will
happen if its frequency is doubled?
a) Pitch decreases b) Loudness increases c) Pitch increases d) Speed double
3. If the frequency of a sound wave is 500 Hz and its wavelength is 0.66 m,
what is the speed of sound?
a) 330 m/s b) 660 m/s c) 250 m/s d) 132 m/s
Assertion Reason Type Questions (1 mark each)
Directions: In each of the following questions, a statement of Assertion is given, and a
corresponding statement of Reason is given just below it. Of the statements, given
below, mark the correct answer as:
(a) Both assertion and reason are true, and reason is the correct explanation of
assertion.
(b) Both assertion and reason are true, but reason is not the correct explanation of
assertion.
(c) Assertion is true, but reason is false.
(d) Assertion is false, but reason is true
4. Assertion (A):Infrasonic sounds are inaudible to humans.
Reason (R): Human ears can detect frequencies between 20 Hz and 20,000 Hz.
5. Assertion (A): Echo is heard when the reflected sound reaches the listener
after 0.1 seconds.
Reason (R): The minimum distance for an echo to be heard is 17.2 m at room
temperature.
6. Why can you hear the sound of a train approaching through the rails earlier than
through air?
7. A) What is SONAR?
B) Find the frequency of a wave whose time period is 0.002 second
8. Read the given passage carefully and give the answer of the following questions:
(1x5)
Two friends Shefali and Anuj make a toy
telephone by joining two plastic cups
through a long string. They both stand
apart. Anuj speaks softly into one cup and
Shefali hears by putting her ear in the other
cup. Now, Shefali speaks and Anuj listens.
