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The quality is the characteristic of sound which distinguishes the two sounds of the same pitch and same loudness.

Correct option is C) Loudness

Quality or timber of sound.

Hollow box is so constructed that the air column inside it has a natural frequency which is same as that of strings stretched on it. So that when the strings are made to vibrate, the air column inside the box is set into vibrations and its reinforces the sound.

When frequency is increased, the pitch of sound increases. When amplitude is increased, its loudness increases.

The sound box is constructed such that the column of the air inside it, has a natural frequency which is the same as that of the strings stretched on it, so that when the strings are made to vibrate, the air column inside the box is set into forced vibrations. Since the sound box has a large area, it sets a large volume of air into vibration, the frequency of which is same as that of the string. So, due to resonance a loud sound is produced.

(a) The loudness of each is same as amplitude is the same.

(b) Pitch of each is same.

(c) Quality is DIFFERENT as the waveform is different

If the two girls are playing with same instruments, then the quality is same. If the girls are playing with different stringed instruments the quality will be different. 

Quality is the characteristic which enables us to distinguish between musical notes emitted by different musical instruments.

Vibrating skin produces the sound. The greater the tension in the skin, the higher is the frequency of the sound. The greater the thickness of the skin, the lower is the frequency of the sound.

i. Consider a transverse progressive wave whose particle position is described by x and displacement from equilibrium position is described by y.

Such a sinusoidal wave can be written as follows:

∴ y (x, t) = a sin (kx – ωt + ø) ……… (1)

where a, k, ω and ø are constants,

y (x, t) = displacement as a function of position (x) and time (t)

a = amplitude of the wave,

ω = angular frequency of the wave

(kx₀ – ωt + ø) = argument of the sinusoidal wave and is the phase of the particle at x at time t.

ii. At a particular instant, t = t₀,

y (x, t₀) = a sin (kx – ωt₀ + ø)

= a sin (kx + constant)

Thus at t = t₀, shape of wave as a function of x is a sine wave.

iii. At a fixed location x = x₀

y(x₀, t) = a sin (kx₀ – ωt + ø)

= a sin (constant – ωt)

Hence the displacement y, at x = x₀ varies as a sine function.

iv. This means that the particles of the medium, through which the wave travels, execute simple harmonic motion around their equilibrium position.

v. For (kx – ωt + ø) to remain constant, x must increase in the positive direction as time t increases. Thus, the equation (1) represents a wave travelling along the positive x axis.

vi. Similarly, a wave travelling in the direction of the negative x axis is represented by,

y(x, t) = a sin (kx + ωt +ø) …….(2)

If the particles of the medium vibrate perpendicular to the direction of wave, then the wave is called a transverse wave.

The regions formed during the longitudinal wave propagation due to change in density are compressions and rarefactions.

C) sound wave

Longitudinal wave: If the particles of the medium vibrate along the direction of the wave, then the wave is called a longitudinal wave.

A wave in which particles of medium vibrate in a direction parallel to the direction of propagation of the wave is called longitudinal wave. 

Example : Sound waves.

It is an acronym which means SOund Navigation And Ranging.

A sonar is a device which measures the distance, direction and speed of objects lying under water using ultrasonic waves.

Sound waves in air are longitudinal.

Yes, sound gets reflected at the surface of a solid as in the case of reflection of light.

We are unable to hear the sound. If we lift one of the pipes then the pipe carrying incident sound, the pipe carrying reflected sound will not be in the same plane. Hence we cannot hear the sound.

Quality of sound produced in the larynx depends upon the tautness of the vocal chords.

Generally, hard surfaces reflect sound better than soft surfaces. But sound reflects quite well from rough surfaces than polished surfaces.

Yes.

1) We know that frequency u = Speed of wave (v) / Wavelength (λ)

2) As speed of wave differs from medium to finedium, the frequency also changes, keeping the wavelengths constant.

• Compressions and rarefactions in a sound wave will be in opposite direction. 
• In a compression, all the particles come close, so the density and pressure increases.
• In a rarefaction, all particles drag back, so the density and pressure decreases. 
• In a microscopic view of particle, the compression and rarefaction travel in opposite directions.

Yes, larynx (vocal cords)

(c) above 20,000 Hz 

(a) frequency

Correct option is: (B) n = \(\frac{v}{λ}\)

Correct option is: (C) 7 m

Higher the pitch, the shriller is the sound. Lower the pitch, the flat (or grave) is the sound.

The pitch of a sound depends on its frequency (i.c., on the frequency of the vibrating body).

• He was an eminent scientist, inventor, engineer, and innovator who is credited with inventing the first practical telephone.
• Bell’s other inventions are including groundbreaking work in optical telecommunications, hydrofoils, and aeronautics.
• In 1888, Bell became one of the founding members of the National Geographic Society

The outer case of the bell in a temple is made big. So that there is multiple reflection of sound and the sound can be amplified.

The time interval between two successive compressions or rarefactions is equal to the time period of the wave.
∴ Required time interval = time period
= \(\frac{1}{Frequency}= \frac{1}{500}\) = 0.002 S
= 2 × 10^-3 S = 2ms.

No, as there is no medium on moon for the sound to travel.

C) undergoing multiple reflections