## MCQ (Single Correct Answer)

An organ pipe filled with a gas at 27$$^\circ$$C resonates at 400 Hz in its fundamental mode. If it is filled with the same gas at 90$$^\circ$$C, the ...

If the initial tension on a stretched string is doubled, then the ratio of the initial and final speeds of a transverse wave along the string is...

In a guitar, two strings A and B made of same material are slightly out of tune and produce beats of frequency 6 Hz. When tension in B is slightly dec...

The fundamental frequency in an open organ
pipe is equal to the third harmonic of a closed
organ pipe. If the length of the closed organ
pipe is 20 cm...

A tuning fork is used to produce resonance in
a glass tube. The length of the air column in
this tube can be adjusted by a variable piston.
At room te...

The two nearest harmonics of a tube closed at one end and open at other end are 220 Hz and 260 Hz. What is the fundamental frequency of the system ?

Two cars moving in opposite directions approach each other with speed of 22 m s$$-$$1 and 16.5 m s$$-$$1 respectively. The driver of the first car blo...

Three sound waves of equal amplitudes have frequencies (n $$-$$ 1), n, (n + 1). They superimpose to give beats. The number of beats produced per seco...

The second overtone of an open organ pipe has the same frquency as the first overtone of a closed pipe L metre long. The length of the open pipe will ...

A siren emitting a sound of frequency 800 Hz moves away from an observer towards a cliff at a speed of 15 m s$$-$$1. Then, the frequency of sound that...

An air column, closed at one end open at the other, resonates with a tuning fork when the smallest length of the column is 50 cm. The next larger leng...

A uniform rope of length L and mass m1 hangs vertically from a rigid support. A block of mass m2 is attached to the free end of the rope. A transverse...

A string is stretched between fixed points separated by 75.0 cm. It is observed to have resonant frequencies of 420 Hz and 315 Hz. There are no othe...

4.0 g of a gas occupies 22.4 litres at NTP. The specific heat capacity of the gas at constant volume is 5.0 J K$$-$$1 mol$$-$$1. If the speed of sound...

A source of sound S emitting waves of frequency 100 Hz and an observer O are located at some distance from each other. The source is moving with a spe...

The fundamental frequency of a closed organ pipe of length 20 cm is equal to the second overtone of an organ pipe open at both the ends. The length of...

If n1, n2 and n3 are the fundamental frequencies of three segments into which a string is divided, then the original fundamental frequency n of the ...

A speeding motorcyclist sees traffic jam ahead him. He slows down to 36 km hour$$-$$1. He finds that traffic has eased and a car moving ahead of him a...

The number of possible natural oscillations of air column in a pipe closed at one end length 85 cm whose frequencies lie below 1250 Hz are (Velocity o...

The length of the wire between two ends of a sonometer is 100 cm. What should be the positions of two bridges below the wire so that the three segment...

Two sources P and Q produce notes of frequency 660 Hz. each. A listener moves from P to Q with a speed of 1 ms$$-$$1. If the speed of sound is 330 m/s...

If we study the vibration of a pipe open at both ends. then the following statement is not true.

A wave travelling in the + ve x-direction having displacement along y-direction as 1 m, wavelength 2$$\pi $$ m and frequency of $${1 \over \pi }$$ Hz...

A source of unknown frequency gives 4 beats/s when sounded with a source of known frquency 250 Hz. The second harmonic of the source of unknown freque...

The equation of a simple harmonic wave is given by
y = 3 sin$${\pi \over 2}$$(50t $$-$$ x),
where x and y are in metres and t is in seconds. The rat...

A train moving at a speed of 220 m s$$-$$1 towards a stationary object, emits a sound of frequency 1000 Hz. Some of the sound reaching the object gets...

When a string is divided into three segments of length $$l$$1, $$l$$2 and $$l$$3 the fundamental frequencies of these three segments are $${\upsilon _...

Two sources of sound placed close to each other, are emitting progressive waves given by
y1 = 4sin600$$\pi $$t and y2 = 5sin608$$\pi $$t
An observe...

Two identical piano wires, kept under the same tension T have a fundamental frequency of 600 Hz. The fractional increase in the tension of one of the ...

Two waves are represented by the equations
y1 = $$a$$sin($$\omega $$t + kx + 0.57) m and
y2 = acos($$\omega $$t + kx) m, where x is in meter and t $...

Sound waves travel at 350 m/s through a warm air and at 3500 m/s through brass. The wavelength of a 700 Hz acoustic wave as it enters brass from warm ...

A transverse wave is represented by
y = Asin($$\omega $$t $$-$$ kx). For what value of the wavelength is the wave velocity equal to the maximum parti...

A tuning fork of frequency 512 Hz makes 4 beats per second with the vibrating string of a piano. The beat frequency decreases to 2 beats per sec when ...

Each of the two strings of length 51.6 cm and 49.1 cm are tensioned separately by 20 N force. Mass per unit length of both the strings is same and equ...

A wave in a string has an amplitude of 2 cm. The wave travels in the +ve direction of x axis with a speed of 128 m/s. and it is noted that 5 complete ...

The driver of a car travelling with speed 30 m/s towards a hill sounds a horn of frequency 600 Hz. If the velocity of sound in air is 330 m/s, the fre...

A point performs simple harmonic oscillation of period T and the equation of motion is given by x = a sin($$\omega $$t + $$\pi $$/6). After the elapse...

Two periodic waves of intensities $$I$$1 and $$I$$2 pass through a region at the same time in the same direction. The sum of the maximum and minimum i...

The wave described by y = 0.25 sin(10$$\pi $$x $$-$$ 2$$\pi $$t), where x and y are in metres and t in seconds, is a wave travelling along the

Two vibrating tuning forks produce waves given by y1 = 4 sin 500$$\pi $$t and y2 = 2 sin506 $$\pi $$t. Number of beats produced per minute is ...

Two sound waves with wavelengths 5.0 m and 5.5. m respectively, each propagate in a gas with velocity 330 m/s. We expect the following number of beats...

The time of reverberation of a room A is one second. What will be the time (in seconds of reverberation of a room, having all the dimensions double of...

A transverse wave propagating along x-axis is represented by y(x, t) = 8.0 sin (0.5 $$\pi $$x $$-$$ 4$$\pi $$t $$-$$ $$\pi $$/4) where x is in metres ...

Which one of the following statements is true ?

A point source emits sound equally in all directions in a non-absorbing medium. Two points P and Q are at distances of 2 m and 3 m respectively from t...

A car is moving towards a high cliff. The driver sounds a horn of frequency $$f$$. The reflected sound heard by the driver has frequency $$2f$$. If v...

The phase difference between two waves. represented by
y1 = 10$$-$$6 sin[100t + (x/50) + 0.5] m
y2 = 10$$-$$6 cos[100t + (x/50)] m,
where x is express...

An observer moves towards a stationary source of sound with a speed 1/5th of the speed of sound. The wavelength and frequency of the source emitted ar...

A whistle revolves in a circle with angular speed $$\omega $$ = 20 rad/s using a string of length 50 cm. If the frequency of sound from the whistle is...

A wave travelling in positive X-direction with a $$=$$ 0.2 ms$$-$$2, velocity = 360 ms$$-$$1 and $$\lambda $$ $$=$$ 60 m, then correct expression for...

Two waves having equation x1 = $$a$$sin($$\omega $$t $$-$$ kx + $$\phi $$1), x2 = asin($$\omega $$t $$-$$kx + $$\phi $$2). If in the resultant wave th...

The equation of a wave is represented by
y $$=$$ 10$$-$$4 sin(100t $$-$$ $${x \over {10}}$$) m. then the velocity of wave will be

If the tension and diameter of a sonometer wire of fundamental frequency n is doubled and density is halved then its fundamental frequency will become...

The equations of two waves acting in perpendicular directions are given as
x = $$a$$cos($$\omega $$t +$$\delta $$) and y = $$a$$cos($$\omega $$t + $$...

Two stationary sources each emitting waves of wavelength $$\lambda $$, an observer moves from one source to another with velovcity u. Then number of b...

A string is cut into three parts, having fundamental frequencies n1, n2, n3 respectively. Then original fundamental frequency n related by the expres...