List of top Physics Questions on Waves asked in JEE Main

A closed organ and an open organ tube filled by two different gases having the same bulk modulus but different densities $\rho_1$ and $\rho_2$ , respectively. The frequency of the 9th harmonic of the closed tube is identical with the 4th harmonic of the open tube. If the length of the closed tube is 10 cm and the density ratio of the gases is $\rho_1 : \rho_2 = 1 : 16$ , then the length of the open tube is:

A sub-atomic particle of mass $10^{-30}$ kg is moving with a velocity of $2.21 \times 10^6$ m/s. Under the matter wave consideration, the particle will behave closely like (h = $6.63 \times 10^{-34}$ J.s)

A sonometer wire of resonating length 90 cm has a fundamental frequency of 400 Hz when kept under some tension. The resonating length of the wire with fundamental frequency of 600 Hz under same tension _______ cm.

A plane progressive wave is given by

y = 2 \cos 2\pi(330t - x) \, \text{m}

. The frequency of the wave is:

A closed organ pipe 150 cm long gives 7 beats per second with an open organ pipe of length 350 cm, both vibrating in fundamental mode. The velocity of sound is ________ m/s.

The equation of a stationary wave is:

y = 2a \sin\left(\frac{2\pi nt}{\lambda}\right) \cos\left(\frac{2\pi x}{\lambda}\right)

Which of the following is NOT correct:

Two waves of intensity ratio

1 : 9

cross each other at a point. The resultant intensities at the point, when (a) Waves are incoherent is

I_1

(b) Waves are coherent is

I_2

and differ in phase by

60^\circ

If

\frac{I_1}{I_2} = \frac{10}{x}

then

x =

_____.

The fundamental frequency of a closed organ pipe is equal to the first overtone frequency of an open organ pipe. If length of the open pipe is 60 cm, the length of the closed pipe will be :

The equation of wave is given by

Y = 10^2 \sin 2 \pi \left( (60t - 0.5x + \frac{\pi}{4}) \right)

where

x

and

Y

are in m and t in s. The speed of the wave is _____ km h

^{-1}

.

The variation of kinetic energy (KE) of a particle executing simple harmonic motion with the displacement (x) starting from mean position to extreme position (A) is given by:

A guitar string of length 90 cm vibrates with a fundamental frequency of 120 Hz. The length of the string producing a fundamental frequency of 180 Hz will be _______ cm.

The width of fringe is 2 mm on the screen in a double slits experiment for the light of wavelength of 400 nm. The width of the fringe for the light of wavelength 600 nm will be:

The power radiated from a linear antenna of length $l$ is proportional to: (Given, $\lambda$ = Wavelength of wave):

Given below are two statement : one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A : EM waves used for optical communication have longer wavelengths than that of microwave, employed in Radar technology.
Reason R : Infrared EM waves are more energetic than microwaves, (used in Radar)
In the light of given statements, choose the correct answer from the options given below:

A beam of light consisting of two wavelengths 7000 Å and 5500 Å is used to obtain interference pattern in Young's double slit experiment. The distance between the slits is 2.5 mm and the distance between the plane of slits and the screen is 150 cm. The least distance from the central fringe, where the bright fringes due to both the wavelengths coincide, is n × 10^-5m. The value of n is_____.

If 917 Å be the lowest wavelength of Lyman series then the lowest wavelength of Balmer series will be _____ Å.

A message signal of frequency 3kHz is used to modulate a carrier signal of frequency 1.5 MHz. The bandwidth of the amplitude modulated wave is

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R
Assertion A: The phase difference of two light waves change if they travel through different media having same thickness, but different indices of refraction.
Reason R: The wavelengths of waves are different in different media.
In the light of the above statements, choose the most appropriate answer from the options given below

As per given figure A, B and C are the first, second and third excited energy level of hydrogen atom respectively. If the ratio of the two wavelengths (ie. $\frac{λ_1}{λ_2}$ ) is $\frac{7}{4n}$ , then the value of n will be____.

A person driving car at a constant speed of 15 m/s is approaching a vertical wall. The person notices a change of 40 Hz in the frequency of his car’s horn upon reflection from the wall. The frequency of horn is ____ Hz.

The fundamental frequency of vibration of a string stretched between two rigid support is 50 Hz. The mass of the string is 18 g and its linear mass density is 20 g/m. The speed of the transverse waves so produced in the string is_______ ms^-1.

A single slit of width a is illuminated by a monochromatic light of wavelength 600 nm. The value of 'a' for which first minimum appears at θ=30° on the screen will be :

The distance between two consecutive points with phase difference of

60^{\circ}

in a wave of frequency

500 \,Hz

is

60\, m

The velocity with which wave is traveling is ___

km / s

The amplitude of $15 \sin (1000 \pi t )$ is modulated by $10 \sin (4 \pi t )$ signal The amplitude modulated signal contains frequency (ies) of
A $500\,Hz$
B $2\, Hz$
C $250\, Hz$
D $498\, Hz$
E $502\, Hz$
Choose the correct answer from the options given below:

The displacement equations of two interfering waves are given by
$y_1=10 \sin \left(\omega t+\frac{\pi}{3}\right)$ cm ,
$y_2=5[\sin \omega t+\sqrt{3} \cos \omega t]$ cm respectively.
The amplitude of the resultant wave is ___ cm