A hearing test is conducted on an aged person. It is found that her threshold of hearing is 20 dB at 1 kHz , and it rises linearly with frequency to, 60 dB at, 9 kHz . The minimum intensity of sound that the person can hear at, 5 kHz is,

0 . 05 times than that at 9 kHz

EASY

Earn 100

The relation between the particles velocity $u$ and wave velocity $v$ is -

50% studentsanswered this correctly

Important Questions on Wave Motion on a String

MEDIUM

Physics>Oscillations and Waves>Wave Motion on a String>Velocity and Acceleration of Particles in Wave Motion

A small speaker delivers

2 W

of audio output. At what distance from the speaker will one detect

120 d B

intensity sound? [Given reference intensity of sound as

10^{- 12} W / m^{2}

]

MEDIUM

Physics>Oscillations and Waves>Wave Motion on a String>Velocity and Acceleration of Particles in Wave Motion

The intensity of sound during the festival season increased by,

100

times. This could imply a decibel level rise from-

MEDIUM

Physics>Oscillations and Waves>Wave Motion on a String>Velocity and Acceleration of Particles in Wave Motion

A tunning fork of frequency

480 H z

is used in an experiment for measuring speed of sound

(v)

in air by resonance tube method. Resonance is observed to occur at two successive lengths of the air column,

l_{1} = 30 c m

and

l_{2} = 70 c m .

Then,

ν

is equal to:

MEDIUM

Physics>Oscillations and Waves>Wave Motion on a String>Velocity and Acceleration of Particles in Wave Motion

When a particle of mass

m

is attached to a vertical spring of spring constant

k

and released, its motion, is described by

y (t) = y_{0} \sin^{2} ωt

, where '

y

' is measured from the lower end of upstretched spring. Then

ω

is :

EASY

Physics>Oscillations and Waves>Wave Motion on a String>Velocity and Acceleration of Particles in Wave Motion

A travelling harmonic wave is represented by the equation

y (x, t) = 10^{- 3} \sin (50 t + 2 x),

where

x

and

y

are in meter and

t

is in seconds. Which of the following is a correct statement about the wave?

EASY

Physics>Oscillations and Waves>Wave Motion on a String>Velocity and Acceleration of Particles in Wave Motion

A uniform thin rope of length

12 m

and mass

6 kg

hangs vertically from a rigid support and a block of mass

2 kg

is attached to its free end. A transverse short wave train of wavelength

6 cm

is produced at the lower and the rope. What is the wavelength of the wave train (in

cm

) when it reaches the top of the rope?

EASY

Physics>Oscillations and Waves>Wave Motion on a String>Velocity and Acceleration of Particles in Wave Motion

A uniform string of length $20 m$ is suspended from a rigid support. A short wave pulse is introduced at its lowest end. It starts moving up the string. The time taken to reach the support is

(Take, $g = 10 m s^{- 2}$ )

MEDIUM

Physics>Oscillations and Waves>Wave Motion on a String>Velocity and Acceleration of Particles in Wave Motion

A transverse wave propagating along $x$ -axis is represented by

$y (x, t) = 8.0 \sin (0.5 π x - 4 π t - \frac{π}{4})$

where $x$ is in meters and $t$ is in seconds. The speed of the wave is

MEDIUM

Physics>Oscillations and Waves>Wave Motion on a String>Velocity and Acceleration of Particles in Wave Motion

A simple harmonic motion is represented by:

y = 5 (\sin 3 π t + \sqrt{3} \cos 3 π t) cm

The amplitude and time period of the motion are:

MEDIUM

Physics>Oscillations and Waves>Wave Motion on a String>Velocity and Acceleration of Particles in Wave Motion

A hearing test is conducted on an aged person. It is found that her threshold of hearing is

20 dB

1 kHz

, and it rises linearly with frequency to,

60 dB

at,

9 kHz

. The minimum intensity of sound that the person can hear at,

5 kHz

is,

MEDIUM

Physics>Oscillations and Waves>Wave Motion on a String>Velocity and Acceleration of Particles in Wave Motion

For a transvers wave travelling, along a straight line, the distance between two peaks (crests) is

5 m

, while the distance between one crest and one trough is

1.5 m

. The possible wavelengths (in

m

) of the waves are:

MEDIUM

Physics>Oscillations and Waves>Wave Motion on a String>Velocity and Acceleration of Particles in Wave Motion

A uniform rope of length

L

and mass

m_{1}

, hangs vertically from a rigid support. A block of mass

m_{2}

is attached to the free end of the rope. A transverse pulse of wavelength

λ_{1}

is produced at the lower end of the rope. The wavelength of the pulse when it reaches the top of the rope is

λ_{2}

. The ratio

\frac{λ_{2}}{λ_{1}}

is:

MEDIUM

Physics>Oscillations and Waves>Wave Motion on a String>Velocity and Acceleration of Particles in Wave Motion

A transverse wave propagating on a stretched string of linear density $3 \times 10^{- 4} {kgm}^{- 1}$ is represented by the equation

$y = 0.2 \sin (1.5 x + 60 t)$

where, $x$ in metres and $t$ is in seconds. The tension in the string (in Newton) is

MEDIUM

Physics>Oscillations and Waves>Wave Motion on a String>Velocity and Acceleration of Particles in Wave Motion

The pressure wave,

P = 0.01 \sin [1000 t - 3 x] N m^{- 2}

, corresponds to the sound produced by a vibrating blade on a day when atmospheric temperature is

0 ° C

. On some other day when temperature is

T

, the speed of sound produced by the same blade and at the same frequency is found to be

336 m s^{- 1}

. Approximate value of

T

is:

EASY

Physics>Oscillations and Waves>Wave Motion on a String>Velocity and Acceleration of Particles in Wave Motion

Sound waves of wavelength

λ

and velocity

v

in medium-

1

enter medium-

2

. If their velocity in medium-

2

4 v

, the wavelength in medium-

2

EASY

Physics>Oscillations and Waves>Wave Motion on a String>Velocity and Acceleration of Particles in Wave Motion

It takes

2.0

seconds for a sound wave to travel between two fixed points when the day temperature is

10 ° C

. If the temperature rises to

30 ° C

, the sound wave travels between the same fixed parts in

EASY

Physics>Oscillations and Waves>Wave Motion on a String>Velocity and Acceleration of Particles in Wave Motion

The air pressure at sea level is

101325 Pa

. At the centre of a rarefaction of a sound wave in air, the pressure is

91000 Pa

. Which is the most likely pressure at the centres of a compression of the same wave?

HARD

Physics>Oscillations and Waves>Wave Motion on a String>Velocity and Acceleration of Particles in Wave Motion

A particle performing S.H.M. starts from the equilibrium position and its time period is

16 s

. After

2 s

its velocity is

π m s^{- 1} .

Amplitude of oscillation is

(\cos 45^{o} = \frac{1}{\sqrt 2})

MEDIUM

Physics>Oscillations and Waves>Wave Motion on a String>Velocity and Acceleration of Particles in Wave Motion

A string of length

1 m

and mass

5 g

is fixed at both ends. The tension in the string is

8 .0 N

. The string is set into vibration using an external vibrator of frequency

100 Hz

. The separation between successive nodes on the string is close to

MEDIUM

Physics>Oscillations and Waves>Wave Motion on a String>Velocity and Acceleration of Particles in Wave Motion

A heavy ball of mass

M

is suspended from the ceiling of a car by a light string of mass

m (m ≪ M) .

When the car is at rest, the speed of transverse waves in the string is

60 m s^{- 1}

. When the car has acceleration

a

, the wave-speed increases to

60.5 m s^{- 1}

. The value of

a

in terms of gravitational acceleration

g

is closed to:

The relation between the particles velocity u and wave velocity v is -

Important Questions on Wave Motion on a String

Learn and Prepare for any exam you want !

The relation between the particles velocity $u$ and wave velocity $v$ is -