Waves practice · Mixed difficulty

Assertion (A) : When a wave travels from a denser medium to rarer medium, then amplitude of oscillation increases.

Reason (R) : In denser medium, speed of wave is less compared to a rarer medium.

Two waves of same frequency and intensity superimpose with each other in opposite phases, then after superposition the

Velocity of sound is maximum in

The equation of a plane progressive waves is given by $y = 0.025\,\,\sin \left( {100\,t + 0.25x} \right)$. The frequency of this wave would be

Assertion: When a beetle moves along the sand within a few tens of centimeters of a sand scorpion, the scorpion immediately turns towards the beetle and dashes towards it.
Reason: When a beetle disturbs the sand, it sends pulses along the sand's surface. One set of pulses is longitudinal while the other set is transverse.

The pitch of a sound wave is related to its

Statement-I: When a sound wave is propagating through the medium, the pressure fluctuations are $/ 2$ out of phase with the displacements.
Statement-II: When a sound wave is propagating through the medium maximum pressure deviation occurs at the positions of zero displacement and no pressure change occur at the positions of maximum displacements.

What is the effect of humidity on sound waves when humidity increases?

A transverse wave of amplitude $0.50 \mathrm{~mm}$ and frequency $100 \mathrm{~Hz}$ is produced on a wire stretched to a tension of $100 \mathrm{~N}$. If the wave speed is $100 \mathrm{~ms}^{-1}$, what average power is the source transmitting to the wire?

Under identical conditions of pressure and density, the speed of sound is highest in a

Apparatus used to find out velocity of sound in gas is

The two waves of the same frequency moving in the same direction give rise to

Stationary waves' are so called because in them

The tones that are separated by three octaves have a frequency ratio of

A man is standing on the platform and one train is approaching and another train is going away with speed of $4\,\,m{s^{ - 1}}$, frequency of sound produced by train is $240\mathrm{ }Hz$. What will be the number of beats heard by him per second?

If the intensities of two interfering waves be $\mathrm{I}_1$ and $\mathrm{I}_2$, the contrast between maximum and minimum intensity is maximum, when

If $x=a \sin [\omega t+(\pi / 3)]$ and $x^{\prime}=a \cos \omega t$, then what is the phase difference between two waves?

Two sound waves are represented by $y = a\,\,\sin \left( {\omega t - kx} \right)$ and $y = a\,\,\cos \left( {\omega t - kx} \right)$. The wavelength of waves in water are

If the temperature increases, then what happens to the frequency of the sound produced by the organ pipe

Vibrations of air column above the surface of water in the tube of a resonance apparatus are

A wave travelling in positive $X$-direction with $A = 0.2\,m$ has a velocity of $360\,\,m/sec.$. If $\lambda = 60\,\,m,$, then correct expression for the wave is

A bullet passes past a person at a speed of $220 \mathrm{~m} / \mathrm{s}$. Find the fractional change in the frequency of the whistling sound heard by the person as the bullet crosses the person. Speed of sound in air $=330 \mathrm{~m} / \mathrm{s}$.

Of the following, the equation of plane progressive wave is

A radar sends radio waves of frequency $v$ towards an aeroplane moving with velocity $v_A$. A change $\Delta v$ is observed in the frequency of reflected wave which is higher than the original frequency. The velocity of aeroplane $\left(v_A < < c\right)$ is

A travelling wave is partly reflected and partly transmitted from a rigid boundary. Let $a_i, a_r$ and $a_t$ be the amplitudes of incident wave, reflected wave and transmitted wave and $I_i, I_r$ and $I_t$ be the corresponding intensities. Then, choose the correct alternative

A SONAR system fixed in a submarine operates at a frequency $40 \mathrm{~kHz}$. An enemy submarine moves towards the SONAR with a speed of $360 \mathrm{~km} / \mathrm{h}$. The frequency of sound is reflected by submarine is (Speed of sound in water $=1400 \mathrm{~m} / \mathrm{s}$)

Equation of progressive wave is:

$y=a \sin ^2 \frac{\pi}{4} \cos ^2 \frac{\pi}{4} \sin (\omega t-k x \pm \phi)$

where symbols having their usual meanings then for given wave equation:

(a) Amplitude $=a \sin ^2 \frac{\pi}{4} \cos ^2 \frac{\pi}{4}$

(b) Wavelength $=\frac{2 \pi}{{K}}$

(c) Unit of $y=$ unit of amplitude, unit of wavelength $=$ unit of $x$

(d) Frequency $=\frac{\omega}{2 \pi}$

The equation of a resultant wave obtained after superposition of two waves is given by $y(x, t)=2 a \sin k x \cos \omega t$. The position of nodes will be given by:

Assertion (A) : Standing waves are formed when amplitudes of two constituent waves are equal.

Reason (R) : At any point net displacement at a given time is resultant of displacement of constituent waves.

A wave travelling along a string is described by the equation $y = a\sin \left( {\omega t - kx} \right)$ the maximum particle velocity is