In constructive interference, the path difference between two interfering waves should be integral multiple of wavelength λ. i.e. x = nλ where n = 0, 1, 2, 3, ......... Similarly, in destructive interference, the path difference .....

For a single source of light, the distribution of energy is uniform. But, for two coherent sources, they produce a non uniform distribution of energy and vary from maximum intensity to minimum intensity. At a point of maximum intensity, the energy .....

Coherent sources: Coherent sources are sources that emit waves of the same frequency and possess a constant phase difference (i.e. phase difference remains constant with time). Two independent sources cannot be coherent because: i. Light is emitted .....

The intensity of  wave is directly proportional to the square of the amplitude.If I1 and I2 are intensities of the two waves y1 = a1 sinωt and y2 = a2 cos ωt then, I1 = a12           and  .....

The fringe width in Young's Double experiment is given by: \(β=\frac{λD}{d} \) When the whole apparatus is immeresed in water, then the refractive index and hence wavelength changes. \(i.e. .....

The fringe width is given by the relation \(β=\frac{λD}{d} \), Where λ, D and d are the wavelengths of light, distance of the screen from the slits and the seperation between the slits .....

Here, λ = 6m For constructive interference, Path difference = nλ      where n = 0, 1, 2, 3, ......... If path difference = 0, 6m, 12m, 18m ....... the points are bright. But 6m, 12m, 18m, ........... do not lie .....

Refraction of Light: Consider a plane wavefront AB incident on a boundary PQ seperating media (1) and (2). Let v1 and v2 respectively be velocity of incident wave and reflected wave (v1 > v2). The first point on boundary to be hit by incident .....

Reflection of light: Consider a plane wavefront ABC incident on a plane reflecting surface PQ. If point A of the wavefront has reached the surface at first, after some time B will reach G and after more time, C will reach E. .....

Huygen's principle states that: (i) Each point on the primary (given) wavefront acts as a source of secondary wavelets, sending out a disturbance in all directions in a similar manner as the original source of light does. (ii) The new position .....

Frequency is the only one physical factor that remains constant when light travels in any medium. This means, when light travels from one medium to another, the change in velocity is due to the change in its wavelength, but not due to the charge in .....

From snell's law, \(µ=\frac{sini}{sinr}.\) If the wavefront is incident normally, i = 0. \(∴µ=\frac{0}{sinr}, or, µsinr=0 \) Since µ ≠ 0 ⇒ .....

During the propagation of the wave, all the particles of the medium which are located at the same distance from the source recive the disturbance simultaneously and vibrate in the same phase. Thus a wavefront of light at any instance is the locus of .....

Locus of all points in the medium which at a given time vibrate with the same phase is called wavefront. The wavefront of a point source is sphere. At any point on the wavefront, the direction of propagation is perpendicular to the .....

Wavefront is defined as the locus of all the particles of a medium vibrating in the same phase at a given instant. The shape of the wavefront depends upon the shape of the source of disturbance. Spherical wavefront: If the soure of disturbance is .....

When a light undergoes refraction, the velocity and wavelength of light get changed but the frequency of light doesn't get changed. This can be explained as: Refraction is the result of the interaction of incident light with the atoms (which may .....

No. When light passes from one medium to another, its speed changes and its wavelengths changes but its frequency doesn't change and its amplitude doesn't change. The energy carried by a wave depends on its amplitude. That's why, the .....

Frequency of the horn (f) = 500 Hz Speed of the car (Vs) = 20 ms-1 Change in frequency = ? Velocity of sound (V) = 340 ms-1 When the car approaches the stationary observer,  \(f'=\frac{v}{v-v_s}×f \) When the car .....

In first case, the observer moves towards the stationary source. \(∴f'=(\frac{v+v_o}{v})×f \)            \(=(\frac{340+33.34}{340})×150×10^3=164.7×10^3Hz .....

Here, vs = 60 km/hr = 16.67 m/s f = 500 Hz vo = 80 km/hr = 22.22 m/s = 340 ms-1 (i) Before overtaking \(f'=\frac{v+u_o}{v+v_S}×f \)           .....

Here, V = 350 m/s Vo = 20 m/s, f = 800 Hz Vs = 20 m/s \(Now,f'=\frac{V+u_o}{V-V_s}×f=\frac{350+20}{350-20}×800=896.96 Hz \)      .....

Consider an observer (O) is moving towards the stationary source of sound (S) with velocity uo. Let v be the velocity and f be the frequency of sound wave emitted by the source. The wavelength of the sound wave is given by  .....

When both are in motion, there will be a change in the wavelength and relative velocity of the waves. The motion of the source affects the wavelength of the wave and motion of the observer affects the relative velocity of the wave. If f' be the .....

A longitundinal wave travelling in x-direction is given by y = a sin(ωt -  kx) Where, ω = angular frequency and k= wave no. Let us consider an imaginary cylinder of air of cross-sectional area A, as shown. Let ∆P be the .....

Doppler's effect: The phenomenon fo apparent change in frequency (pitch) of sound due to the relative motion of the source and the observer (listener) is called Doppler's effect. This effect is equally applied in the case of light .....

Intensity of sound: It is the rate of flow of sound energy through a unit area perpendicular to the direction of propagation of sound. It is deneoted by I. \(Intensity(I)=\frac{Energy}{Area×time} \) .....

The rate of flow of sound (wave) energy through a unit area is called the intensity of sound.It is measure in Wm-2. The difference in loundness between two sounds is called intensity level. It is measured in bel.  The relation between these two .....

One can recognize a friend frm his voice without seeing him. Human voice has a large number of frequencies which are simple multiples of a minimum frequency. It is called the fundamental freqency. The frequencies which are simple multiple of the .....

Threshold of hearing: The loudness of a musical sound is directly proportional to the surface area of the vibrating body. Greater is the area of the vibrating body, larger is the rate of energy transmitted into the medium and hence higher is the .....

Loudness we sense is related to the intensity of sound through it is not directly proportional to it. It also depends upon the sensitivity of the individual ear. For a given frequency, the greater the pressure amplitude of a a sinusiodal wave, the .....

Ultrasonic: Longitudinal oscillations and waves of a frequency higher than 20 KHz are called ultrasonics. Ultrasonics are produced by suitable materials vibrating at these high frequencies. Infrasonic: Longitudinal oscillations and waves of a .....

According to Doppler's effect, the frequency received by a stationary observer (listner) when the sound source is approaching him/her, is given by \(f'=\frac{v}{v-u_t}×f \) where v is the velocity of sound, ut is .....

The relation between the intensity of sound and pressure amplitude is given by \(I=\frac{(△Pm)^2}{2ρv} \) where △Pm ⟶ Pressure amplitude Now, if the pressure amplitude is halved, then, .....

A longitundinal wave propagates in any medium by making compression (a region of high density) and refraction (a region of lower density). Due to the alternte compression and rarefaction, the volume of the medium is varied resulting the variation of .....

The shrillness in a voice is called pitch, which is directly proportional to the frequency. Since the frequency of a woman is more than that of a man, the voice of a woman is more .....

We have the relation I ∝ A2, where I is the intensity of sound produced by the particles of a medium and A is the amplitude of vibration of the particles. When we strike a vessel filled with water, the water molecules vibrate with small .....

Mass (m) = 40 gm = 4 × 10-3 kg Length (l) = 80 cm = 80 × 10-2 m Fundamental frequency (fo) = 60 Hz Speed (v) = ? Tension (T) = ? We know, \(f_o=\frac{1}{2l}\sqrt{\frac{T}{µ}} \) .....

Speed of sound (v) = 345 m/s Fundamental frequency for closed pipe (f1) = 220 Hz Now, Second overtone of the closed pipe = 5f1 = 5 × 220 = 1100 Hz Again, Third harmonic of an open pipe \(=3f_1=3.\frac{v}{2l} .....

Here, diameter (d1) = 0.9 mm = 9 × 10-4 m Diameter (d2) = 0.93 mm = 9.3 × 10-4 m We have, \(f=\frac{1}{ld} \sqrt{\frac{T}{πρ}} \) .....

l =  20 cm = 0.2 m m = 5 g = 5 × 10-3 kg T = 500 N f = ? We know, \(f=\frac{1}{2l}\sqrt{\frac{T}{µ}}=\frac{1}{2l}\sqrt{\frac{T}{\frac{m}{l}}}=\frac{1}{2l}\sqrt{\frac{T×l}{m}} \)   .....

Laws of Transverse vibration of strings: The frequency of fundamental note of vibration of a stretched string is given by \(f=\frac{l}{2l}\sqrt{\frac{T}{µ}} \) where l = length of string T= Tension applied µ .....

The organ pipe which is closed at one end and open at another end is called closed pipe. Similarly, the organ pipe which is open at both ends is called open pipe. The number of nodes and antinodes are equal in closed pipe. But, in open pipe, the .....

The 'resonance tube apparatus' consists of a long glass tube AB of uniform internal diamater. The tube is fixed on a vertical board along the side of a meter scale. The zero of scale coincides with upper end of the tube. The lower end of the .....

Open Organ Pipe: When a sound source is held near the open end of pipe, it is set into vibrations and a series of alternate compressions and rarefactions is generated within pipe. These waves, as they reach the open end come back to the vibrating .....

Harmonics and overtones: The different modes of frequency that a musical instrument can produce are called harmonics. All the modes of vibrations other than the fundamental frequency are called overtones. When the overtones have frequencies in excat .....

The speed of a vibrating particle of the medium is different at its different positions in a vibration but the speed of the wave motion is always constant. In other words, the particle speed varies with time, while the wave speed is independent of .....

The degree of sensation of sound in the human ear due to the sensation of the sound is called the loudness of sound. It depends on many factors like intensity, the amplitude of vibration, distance from the listener, etc. It also depends on the .....

When a tuning fork is set into vibration, its prongs are always moving in opposite phases in such a way that the centre of gravity of the tuning fork does not change. This doesn't require external force to maintain vibrations. It will continue .....

The fundamental frequency of organ pipe is given by \(f=\frac{V}{γ} \) But, when end correction is considered, λ = 4 (l +e) for closed pipe and λ = 2(l + 2e) for open pipe .....

The velocity of the transverse wave propagating through the string is given by \(v=\sqrt{\frac{T}{m}} \) where, T is the tension in the string and m is the mass per unit length of the string. When the tension in the .....