Tag: oscillation - amplitude, time period and frequency of oscillation

Questions Related to oscillation - amplitude, time period and frequency of oscillation

Which is true for a wave ? (here n = frequency, T = time period)

physics sound: production of sound oscillation - amplitude, time period and frequency of oscillation time period, frequency and amplitude of sound oscillatory and periodic motion

  1. nT$=1$

  2. $\displaystyle\frac{n}{T}=2$

  3. n=T

  4. None of these

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Correct Option: A
Explanation:

Frequency is , number of vibrations per (one) second , and time period is the time taken to complete one vibration .

      Let a vibrating body completes n vibrations in 1 s ,
therefore time taken to complete one vibration , $T=(1/n)$ second
  therefore we have , $T=1/n$ ,

            or                  $nT=1$

What is the time period of a wave having frequency of 50 Hz?

physics sound: production of sound oscillation - amplitude, time period and frequency of oscillation time period, frequency and amplitude of sound oscillatory and periodic motion

  1. 0.02 s

  2. 0.20 s

  3. 2.0 s

  4. 20 s

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Correct Option: A
Explanation:

$\text {Time period} = \dfrac{1}{\text{frequency}}= \dfrac{1}{50}=\ 0.02 \ s$

A sound wave completes $24$ cycles in $0.8\;s$. The time period of the wave would be:

physics sound: production of sound oscillation - amplitude, time period and frequency of oscillation time period, frequency and amplitude of sound oscillatory and periodic motion

  1. $1/30\;s$

  2. $30\;s$

  3. $1/24\;s$

  4. $24\;s$

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Correct Option: A
Explanation:

A time period is the time taken to complete one cycle.


Given that, the sound wave completes $24$ cycles in $0.8\,s$

So, the time taken to complete one cycle $=\dfrac{0.8}{24}=\dfrac{1}{30}\,s$

Hence the time period is $\dfrac{1}{30}\,s$

The time period of a vibrating body is $0.01\;sec$. Its frequency will be :

physics sound: production of sound oscillation - amplitude, time period and frequency of oscillation time period, frequency and amplitude of sound oscillatory and periodic motion

  1. $1.0\;s^{-1}$

  2. $10.0\;s^{-1}$

  3. $100.0\;s^{-1}$

  4. $1000.0\;s^{-1}$

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Correct Option: C
Explanation:

Given,


Time period $=0.01\,sec$

We have to find the frequency

We have the relation,

$Frequency=\frac{1}{Time\,Period}$

That is,

$Frequency=\frac{1}{0.01}=100\,s^{-1}$

A man blows a whistle and hears an echo after 1.2 seconds. The distance between the man and the reflector of the sound is _____ m. (take velocity of sound in air as $330 {ms}^{-1}$)

physics sound: production of sound oscillation - amplitude, time period and frequency of oscillation time period, frequency and amplitude of sound oscillatory and periodic motion

  1. 250

  2. 190

  3. 298

  4. 198

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Correct Option: D

A source of sound is moving away from an observer at rest with a velocity $50 {ms}^{-1}$. If the frequency of sound is 200 Hz, find the apparent frequency observed by the observer. (Take velocity of sound = $300 {ms}^{-1}$)

physics sound: production of sound oscillation - amplitude, time period and frequency of oscillation time period, frequency and amplitude of sound oscillatory and periodic motion

  1. 140 Hz

  2. 25.1 Hz

  3. 171.4 Hz

  4. 75.6 Hz

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Correct Option: C

The frequency of sound waves can be expressed in 

physics sound: production of sound oscillation - amplitude, time period and frequency of oscillation time period, frequency and amplitude of sound oscillatory and periodic motion

  1. Hz

  2. $cycle/second$

  3. $s^{-1}$

  4. all the above

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Correct Option: D
Explanation:

The frequency of a wave is the number of waves passing a point in a certain time. The SI unit of frequency is $Hz$. One Hz is equal to one cycle per second.

We also have the relation between the frequency and the time period as:
$f=\frac{1}{T}$
The time is measured in seconds. So the frequency can also be expressed as $s^{-1}$

If the tension in a stretched string is quadrupled, find the change in the fundamental frequency of the transverse wave that can be created in the stretched string.

physics sound: production of sound oscillation - amplitude, time period and frequency of oscillation time period, frequency and amplitude of sound oscillatory and periodic motion

  1. thrice the original frequency

  2. 1/2 (original frequency)

  3. original frequency

  4. twice the original frequency

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Correct Option: C

The average speed of the to bob of a seconds pendulum is $2 {ms}^{-1}$. Determine the frequency of oscillation.

physics sound: production of sound oscillation - amplitude, time period and frequency of oscillation time period, frequency and amplitude of sound oscillatory and periodic motion

  1. 0.5 Hz

  2. 1.5 Hz

  3. 0.9 Hz

  4. 2 Hz

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Correct Option: A

Which of the following sounds have the highest frequency?
a) A man shouting.
b) The sound of a whistle.
c) A lion's roar.
d) The sound of a drum.

physics sound: production of sound oscillation - amplitude, time period and frequency of oscillation time period, frequency and amplitude of sound oscillatory and periodic motion

  1. a

  2. b

  3. c

  4. d

Show answer
Correct Option: B
Explanation:

Low frequency sounds are low pitched like that of a man shouting, a lion's roar, sound of a drum, etc.