Waves PYQs - Last 10 Years

A train is moving towards a stationary observer with speed $34$ m/s. A train sounds a whistle of frequency $450$ Hz. If the speed of sound is $340$ m/s, the frequency heard by the observer in Hz is

The ratio of the speed of sound in helium gas to that in nitrogen gas at $295$ K is ( Ratio of specific heats $\gamma$ for helium is $\dfrac{5}{3}$ and that for nitrogen is $\dfrac{7}{5}$. Molecular weight for helium and nitrogen are $4$ an...

A tuning fork of frequency '$n$' is held near the open end of a tube which is dipped in water and length of the tube is adjusted until resonance occurs. If the two shortest lengths that produce resonance are $l_1$ and $l_2$, the speed of so...

The 'Loudness' and 'Pitch' of sound respectively are the human perception to

A wire of length '$L$', diameter '$d$', density of material '$\rho$' is under tension '$T$' has fundamental frequency of vibration '$n_A$'. Another wire of length '$2L$', diameter '$3d$', density of material '$2\rho$' is vibrated under tens...

The equation of a wave on a string of linear mass density $0.02\ \text{kg m}^{-1}$ is $Y = 0.01\sin\left[2\pi\left(\dfrac{t}{0.02} - \dfrac{x}{0.50}\right)\right]$ m. The tension in the string is

Two waves are represented as$y_1 = a_1\sin\left(\omega t - \dfrac{2\pi x}{\lambda}\right)$ and$y_2 = a_2\cos\left(\omega t - \dfrac{2\pi x}{\lambda} + \dfrac{\pi}{6}\right)$The path difference between two waves is

Two monoatomic ideal gases '1' and '2' of molecular masses $m_1$ and $m_2$ respectively are enclosed in separate containers kept at the same temperature. The ratio of the speed of sound in gas '1' to that in gas '2' is

Two sound waves each of wavelength $\lambda$ and same amplitude $A$ interfere at point $Q$. If the path difference is $\dfrac{\lambda}{4}$, the amplitude of the resultant wave at point $Q$ is $\left[\sin\dfrac{\pi}{2} = 1, \cos\dfrac{\pi}{2...

Which one of the following statements regarding pitch of sound is 'WRONG' ?(A) Pitch refers to sharpness of sound.(B) Tone refers to the single frequency of that wave.(C) High pitch sound need not be louder.(D) In general male sound is shar...

A set of $14$ tuning forks is arranged in a series of increasing frequencies. Each fork produces '$x$' beats per second with the preceding fork and the last fork is an octave of the first fork. If the seventh fork has the frequency of $114$...

A tuning fork gives $5$ beats per second with a $33$ cm length of sonometer wire. If the length of the wire is shortened by $1$ cm, the number of beats is still the same. The frequency of the fork is

The third overtone of a closed pipe of length '$L_c$' has the same frequency as the third overtone of the open pipe of length '$L_0$'. Both the pipes have same diameters. The ratio $L_c : L_0$ is equal to

A body sends a wave $150$ mm long through medium P and $0.30$ m long in medium Q. If velocity of the wave in medium P is $80\,\text{cm s}^{-1}$, the velocity of wave in medium Q is

The equation of a progressive wave is given by $y = 6\cos(100t - 4x)$ where $y$ is in $\mu\text{m}$, $x$ in metre and $t$ in second. The ratio of the maximum particle velocity to the velocity of wave is

Two waves of same frequency ($n$) approaching each other with same velocity of $18$ m/s interfere. The distance between two consecutive antinodes is

For stationary wave, $y = 12\cos\left(\dfrac{\pi x}{10}\right)\sin(36\pi t)$ cm, the distance between a node and the successive antinode is

In a resonance tube open at one end, the end correction is $1.1$ cm. If the shortest length of resonating air column with a tuning fork is $18$ cm, the next resonating length will be

The number of waves counted by an observer on the sea-coast in one minute is 54. If the wavelength of the waves is $5\ \text{m}$ then the velocity of the waves in $\text{m/s}$ will be

The lengths of the two pipes open at both ends are L and $(L + L_1)$. If they are sounded together, the beat frequency will be($v$ = velocity of sound in air)

Fifth overtone of an open pipe of length $L_0$ is in unison with the fifth overtone of the pipe closed at one end of length $L_c$.The ratio $L_0$ to $L_c$ is

Two sources of sound are emitting progressive waves $y_1 = 4\sin 708\,\pi t$ and $y_2 = 3\sin 700\,\pi t$. The sources are placed close to each other. The number of beats heard per second and intensity ratio between waxing and wanning are r...

A person standing between two parallel cliffs fires a gun and hears two echoes, first echo after 1 second and second echo after 3 second. The distance between the two cliffs is (The velocity of sound $= 330$ m/s)

A wire of length 'L' and linear density 'm' is stretched between two rigid supports with tension 'T'. It is observed that wire resonates in the $P^{th}$ harmonic at a frequency of 320 Hz and resonates again at next higher frequency of 400 H...

The fundamental frequency '$n$' of the tuning fork is 288 Hz, it will not resonate with the frequency

In an organ pipe closed at one end produces a fundamental note of frequency '$\nu$'. The pipe is cut into two pipes of equal length. The fundamental frequencies produced in the two pipes are

The enclosed air inside a closed box of rigid walls has pressure $P_1$. The density of air inside this box is constant. On heating the gas, the pressure of the enclosed air is increased from $P_1$ to $P_2$. Now it is observed that the sound...

Out of the following musical instruments which is ' NOT ' a percussion instrument?

In case of stationary wave pattern, which of the following statement is CORRECT ?

A and B are two wires whose fundamental frequencies are 256 Hz and 382 Hz respectively. When third harmonic of A and the second harmonic of B are sounded together, the number of beats heard in two second will be

Two sounding waves send waves at certain temperature in air of wavelength 50 cm and 50.5 cm repectively. The frequency of sources differ by 6 Hz. The velocity of sound in air at same temperature is

In a pipe closed at one end, air column is vibrating in the fourth overtone so the vibrating air column has '$x$' nodes and '$y$' antinodes. The values of $x$ and $y$ are respectively

The beats are produced when there is a superposition of two sound waves which will have

In a sonometer experiment, the fundamental frequency of vibration of wire is '$n_1$' when wire is stretched by hanging a metal bob. If the bob is completely immersed in water, the frequency of vibration of wire becomes '$n_2$'. The relative...

The equation of wave motion is $Y = 6\sin\left(12\pi t - 0.02\pi x + \dfrac{\pi}{3}\right)$ where x is in metre and time in second. The velocity of the wave is

When the observer moves towards a stationary source with velocity '$V_1$', the apparent frequency of the emitted note is '$F_1$'. When the observer moves away from the source with velocity '$V_1$', the apparent frequency is '$F_2$'. If 'V' ...

When a sonometer wire vibrates in the third overtone, the number of antinodes and nodes formed on the wire are respectively

A progressive wave of frequency 50 Hz is travelling with velocity 350 m/s through a medium. The change in phase at given time interval of 0.01s is

A person observes two moving trains. 'A' reaching the station and 'B' leaving the station with equal speed of 30m/s. If both trains emit sounds with frequency 300 Hz, (speed of sound = 330 m/s) difference of frequencies heard by the person ...

When open pipe is closed from one end then third overtone of closed pipe is higher in frequency by 150Hz than second overtone of open pipe. The fundamental frequency of open end pipe will be (Neglect end correction)

Two waves $Y_1 = 0.25\sin 316t$ and $Y_2 = 0.25\sin 310t$ are propagating along the same direction. The number of beats produced per second are

An air column in a pipe which is closed at one end will be in resonance with a vibrating tuning fork of frequency 415 Hz for various vibrating air columns. Which one of the following lengths is not in resonance ? (velocity of sound in air =...

The fundamental frequency of sonometer wire is $50$ Hz for some length and tension. If the length is increased by $25\%$ by keeping the tension same, then the frequency change of second harmonic is

A sonometer wire resonates with $4$ antinodes between the two bridges for a given tuning fork when $1$ kg mass is suspended from the wire. Using same fork, when mass M is suspended, the wire resonates producing $2$ antinodes between the two...

A Pipe open at one end has length $0.8$ m. At the open end of the tube a string $0.5$ m long is vibrating in its first overtone and resonates with fundamental frequency of pipe. If tension in the string is $50$ N, the mass of string is (Neg...

A wire is under tension of $2$ kg wt and a wave is travelling through it with some speed. Tension in the wire is so increased that the wave travels through it with thrice the original speed. The increase in tension is (in kg wt)

When open pipe is closed from one end then second overtone of closed pipe is higher in frequency by 100 Hz than first overtone of open pipe. The fundamental frequency of open end pipe will be (Neglect end correction)

To increase the frequency of transverse oscillations of a stretched string by 40%, the tension must be increased by

A pipe open at both ends has a fundamental frequency 'f' in air. The pipe is dipped in water, so that $\dfrac{2}{3}^{rd}$ length of pipe is in water, Now the fundamental frequency of the air column is

A simple harmonic progressive wave is represented by $y = A \sin(120\pi t + 3x)$. The distance between two points on the wave at a phase difference of $\dfrac{\pi}{3}$ radian is