Characteristics of Sound

A string in a musical instrument is $50\mathrm{cm}$ long and its fundamental frequency is $800\mathrm{Hz}$. If a frequency of $1000\mathrm{Hz}$ is to be produced, then required length of string is

What is a fundamental for a musical instrument?
 

Pitch and Frequency of Sound are:

A person whistles with the power of $0.63 \times {10}^{-3} \mathrm{W}$. The sound intensity at a distance of  $9 \mathrm{m}$ is $k\times {10}^{-5} \mathrm{W}/{\mathrm{m}}^2$. Then what is the value of $k$?

State that whether the given statement is true or false.

$0$ decibel means that there is no sound.

Decibel scale is a _____ scale.

Loudness depends upon the _____ of the amplitude of the sound wave.

Select the loudness of whisper.

Loudness of sound increases with 

Loudness of sound is measured in decibels.

When string is plucked at one-fourth length from one end, the vibration of the string is called _____ (First/Second) harmonic.

Two waves of the same pitch have their amplitude in the ratio $2:3$. What will be the ratio of their frequencies?

The intensity of sound is measured in a unit called -

Noise level is measured in _____.

How much intense is $80 dB$ sound in comparison to $40 dB?$

The power of sound from the speaker of radio is $10 \mathrm{W}$. Now, the power of sound from the speaker of the radio is increased to $400 \mathrm{W}$ by increasing the volume of the radio. The power increased in $\mathrm{dB}$ as compared to original power is nearly

Two loudspeakers are being compared. One is perceived to be $32$ times louder than the other. The difference in intensity levels between the two, when measured in decibels, is

(Note: Human mind perceives doubling of loudness for each $10 \mathrm{dB}$ change)

Two identical sound $A$ and $B$ reach a point in the same phase. The resultant sound is $C$. The loudness of $C$ is $n \mathrm{dB}$ higher the loudness of $A$.

A sound absorber attenuates the sound level by $20 \mathrm{dB}$. The intensity decreases by a factor of

The ratio of intensities between two coherent sound sources is $4 :1$. The difference of loudness in decibels $\left(\mathrm{d}\mathrm{B}\right)$ between maximum and minimum intensities, on their interference in space is