Waves practice · Medium

An observer is standing $500\,\,m$ away from a vertically hill. Starting between the observer and the hill a police van having a siren of frequency $1000\,\,Hz$ moves towards the hill with a uniform speed. If the frequency of the sound heard directly from the siren is $970\,\,Hz$, the frequency of the sound heard after reflection from the hill (in Hz) is about, (velocity of sound =$330\,\,m{s^{ - 1}}$

For an interference pattern, the maximum and minimum intensity ratio is $64: 1$, then what will be the ratio of amplitudes?

Phase difference between a particle at a compression and a particle at the next rare fraction is

Two waves travelling in a medium in the x-direction are represented by , ${y_1} = A\sin \left( {\alpha t - \beta x} \right)$ and ${y_2} = A\cos \left( {\beta x + \alpha t - \pi /4} \right)$ where ${y_1}\;\,\,and\,\,\mathrm{ }{y_2}$ are the displacements of the particles of the medium, t is time, and  $\alpha \,and\,\beta$ are constants. The two waves have different

a segment of wire vibrates with a fundamental frequency of $450\,\,Hz$ under a tension of $9\mathrm{ }kg - wt$. then tension at which the fundamental frequency of the same wire becomes $900\,\,Hz$ is

The path difference between two interfering waves at a point on screen is 171.5 times the wavelength. If the path difference is 0.01372 cm. Find the wavelength?

Statement I: Sonometer is used to determine frequency of unknown T.F.

Statement II: In sonometer riders used as indicator.

Assertion: Transverse waves are not produced in liquids and gases.
Reason: Light waves are transverse-like waves.

Assertion: In reflection of waves, frequency of waves remains same but their phase changes continuously.
Reason: When same sound note is heard after reflection from an obstacle, then it is known as echo.

The energy per unit area associated with a progressive sound wave will be doubled if

A fork of unknown frequency when sounded with one of frequency $288 \mathrm{~Hz}$ gives 4 beats per second and when loaded with a piece of wax again gives 4 beats per second. How do you account for this and what was the unknown frequency?

Transverse waves are generated in two uniform steel wires $A$ and $B$ by attaching their free ends to a fork of frequency $500 \mathrm{~Hz}$. The diameter of wire $A$ is half that of $B$ and tension in wire $A$ is half the tension in wire $B$. What is the ratio of velocities of waves in $A$ and $B$ ?

A man stands in a narrow, steep-sided valley. When he shouts, he hears two echoes, one after $1 \mathrm{~s}$ and other after $2 \mathrm{~s}$. If the velocity of sound in air is $330 \mathrm{~m} / \mathrm{s}$, the width of the valley is

At a certain instant a stationary transverse wave is found to have maximum kinetic energy. The appearance of string at that instant is

A transverse wave described by
$y=(0.02 \mathrm{~m}) \sin \left[\left(1.0 \mathrm{~m}^{-1}\right) x+\left(30 \mathrm{~s}^{-1}\right) t\right]$ propagates on a stretched string having a linear mass density of $1.2 \times 10^{-4} \mathrm{~kg} \mathrm{~m}^{-1}$. Find the tension in the string.

The waves associated with the motion of microscopic particles such as electrons, protons, neutrons are called

The equation of the standing wave in a string clamped at both ends, vibrating in its third harmonic is given by

${y}=0.4 \sin (0.314 {x}) \cos (600 \pi {t})$ where ${x}$ and ${y}$ are in cm and ${t}$ is in sec-

The rms speed of hydrogen at $27^{\circ} \mathrm{C}$ is $v$. The rms speed of oxygen at $1200 \mathrm{~K}$ is

The equation of a transverse wave on a stretched string is given by $y=0.05 \sin 2 \pi\left(\frac{t}{0.002}-\frac{x}{0.1}\right)$, where $x$ and $y$ are expressed in metre and $t$ in second. The speed of the wave is

If speed of sound in air at $27^{\circ} \mathrm{C}$ is $v$ then at what temperature speed of sound becomes $2 v$ ?

A stone is dropped into a lake from a tower $500\,\,metre$ high. The sound of the splash will be heard by the man approximately after

A sound carried by air from a guitar to a listener is a wave of following type

It takes $2.0\mathrm{ }s$ for a sound wave to travel between two fixed points when the day temperature is $10^\circ C$. if the temperature rises to $30^\circ C$ the sound wave travels between the same fixed parts in

Amplitude of a mass -spring system, which is executing simple harmonic motion decreases with time. If mass $= 500\,g$ decay constant $= 20\,g/s,$ then how much time is required for the amplitude of the system to drop to half of its initial value? $(\mathrm{In}\,2 = 0.693)$

Change in temperature of the medium changes

Two sources of sound are in resonance when

Assertion: Resonance is a special case of forced vibration in which the natural frequency of vibration of the body is the same as the impressed frequency and the amplitude of forced vibration, is maximum.
Reason: The amplitude of forced vibration of a body increases with an increase in the frequency of the externally impressed periodic force.

Assertion :- A tuning fork is in resonance with a closed pipe in fundamental mode but the same tuning fork cannot be in resonance in fundamental mode with an open pipe of same lengths

Reason :- The same tuning fork will not be in Resonance with open pipe of same length is due to end correction of pipe

A string is producing transverse vibration whose equation is $y = 0.021\sin \left( {x + 30t} \right)$, Where $x$ and $y$ are in meters and $t$ is in seconds. If the linear density of the string is $1.3\,\, \times \,\,{10^{ - 4}}\,\,kg/m$, then the tension in the string is $N$ will be

The ratio of frequencies of fundamental harmonic produced by an open pipe to that of closed pipe having the
same length is