Tag: nature and characteristics of sound waves

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Questions Related to nature and characteristics of sound waves

Multiple choice physics sound time period, frequency and amplitude of sound amplitude, time period and frequency of a vibration nature and characteristics of sound waves

If the intensity of sound increases by a factor of $10^5$ , the increases in the intensity level is

  1. $5db$
  2. $10db$
  3. $25db$
  4. $50db$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The change in sound intensity level in decibels is calculated using the formula delta L = 10 log10(I2/I1). Given that the intensity increases by a factor of 10^5, substitute this into the formula to get 10 log10(10^5) = 10 * 5 = 50 dB. Therefore, the increase in the intensity level is 50 db.

Multiple choice physics sound time period, frequency and amplitude of sound amplitude, time period and frequency of a vibration nature and characteristics of sound waves

In a class of $100$ students each shouting at $100 dB$. Find noise level of class

  1. $10 dB$
  2. $100 dB$
  3. $12 dB$
  4. $120 dB$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The sound level of N identical independent sources each at level L is given by the formula L_total = L + 10 log10(N). Here, N = 100 students and each shouts at 100 dB. Calculating the addition gives 100 + 10 log10(100) = 100 + 10 * 2 = 120 dB.

Multiple choice physics sound time period, frequency and amplitude of sound amplitude, time period and frequency of a vibration nature and characteristics of sound waves

The fundamental frequency of a closed organ pipe is same as the first overtone frequency of an open pipe. The length of open pipe is $20\ cm$. The length of closed pipe is

  1. $25\ cm$
  2. $12.5\ cm$
  3. $13.33\ cm$
  4. $200\ cm$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Given $:- $
Fundamental Frequency for the Open orange pipe $= ν/2l'$
where$, ν =$ Frequency and l' is the length of the open orange pipe$.$
Third Harmonic of the orange pipe $= 3ν/4l$
where$, ν =$ frequency 
and $l$ is the length of the Closed orange pipe $= 20 cm.$
Now$,$ According to the Question$,$
$3ν/4l = ν/2l'$
$⇒ 3/(4 × 20) = 1/2l'$
$⇒ 3/80 = 1/2l'$
$⇒ 2l' = 80/3$
$⇒ l' = 40/3$
$⇒ l' = 13.33 cm.$
Hence,
option $(C)$ is correct answer.
Multiple choice physics sound time period, frequency and amplitude of sound amplitude, time period and frequency of a vibration nature and characteristics of sound waves

If the amplitude of a wave is doubled, what will be the effect on its loudness ?

  1. increase four times

  2. increase two times

  3. decrease four times

  4. decrease two times
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Loudness depends on the square of the amplitude of the wave. 


That is, $loudness\propto { \left( amplitude \right)  }^{ 2 }$

Thus, when amplitude of the wave is doubled, the loudness becomes four times.

Multiple choice physics sound time period, frequency and amplitude of sound amplitude, time period and frequency of a vibration nature and characteristics of sound waves

Which of the following factors change when a sound gets louder?

  1. intensity

  2. Speed of the sound wves

  3. frequency

  4. decibel level

  5. wavelength

  6. amplitude
Reveal answer Fill a bubble to check yourself
A,D,F Correct answer
Explanation

When a sound gets louder , its amplitude increases , as intensity $I\propto A^{2}$ (amplitude) , therefore intensity of sound also increases , which in turn increases level of intensity i.e. decibel .

Multiple choice physics sound time period, frequency and amplitude of sound amplitude, time period and frequency of a vibration nature and characteristics of sound waves

With the increase in frequency a sound becomes louder. True or false

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Increased frequency means decreased wavelength and higher pitch/ sharpness. So increase in frequency makes sound more sharper while higher amplitude or higher intensity makes louder sound. 

Multiple choice physics sound time period, frequency and amplitude of sound amplitude, time period and frequency of a vibration nature and characteristics of sound waves

A vibrating tuning fork is first held in the hand and then its end is brought in contact with a table. Which of the following statement(s) is/are correct in respect of this situation?

  1. The sound is louder when the tuning fork is held in hand.

  2. The sound is louder when the tuning fork is in contact with table.

  3. The sound dies away sooner when tuning fork is brought in contact with the table.

  4. The sound remains for a longer duration when turning fork is held in hand.
Reveal answer Fill a bubble to check yourself
B,C,D Correct answer
Explanation

when the tuning fork is held in hand there is only air in contact to the fork and sound waves force the air particles to vibrate but when the fork is in contact with the table the sound waves will travel in table as well as air which is in contact with table top. The sound dies sooner as the waves travel much faster in solids and liquids than in gases.