Question

What do you mean by interference?

Answer 1

Hint: The question is asked from the chapter wave optics. Light has dual nature waves and particles both under the effect of electric and magnetic fields. Interference is the phenomenon of wave optics. In real world interference means coming in between of something. Here in physics two waves of same frequency and phase difference interfere with each other and show a pattern of bright and dark fringes.

Complete step-by-step answer:
Step 1:
Interference is the phenomenon of superimposition of two or more waves having the same frequency emitted by coherent sources such that amplitude of resultant wave is equal to the sum of the amplitude of the individual waves. The amplitude of resultant waves can either be larger or smaller than of individual waves depending on whether the interference is constructive or destructive.
To understand this a scientist Young has done an experiment to confirm the wave nature of photons and also explained the working of it and shown the interference of the light.

Step 2:
For clear vision we have a diagram of Young’s double slit experiment.
This is an experiment which brings out the bright and dark fringes from a source. This source is a beam of light or photons going through two holes equal to the wavelength that means the difference between the holes is very small and the fringes obtain on the other screen.

Step 3:
For better understanding and working of the experiment there is a diagram below.

A labeled diagram is provided the distance between the slit is ‘d’ and the distance between the screens are D. An electron beam or beam of light or beam of photons in bombarded on the slits and according to their nature they produce interference pattern and fringes dark and bright obtain on screen.

Working:
Young’s double slit experiment uses two coherent sources of light placed at a small distance d slightly greater or equal to the wavelength of light. It helps in understanding the wave theory of light. Screen is placed at distance D.
At any point on the screen at a distance ‘y’ from the centre, the waves travel distance and from the hole 1 and 2. The path difference is created by the points. The point subtends at an angle but D is very large so there is a very small difference of angle subtended at source.

Step 3: Here with the help of this experiment he explained clearly the wave theory of light doing interference and showing constructive and destructive interference.

Additional information:
Wave nature of light – The wave nature of light is given by James Clerk Maxwell in 1864. He led to the view that light is of electromagnetic nature, propagating as a wave from the source to the receiver. Heinrich Hertz discovered experimentally the existence of electromagnetic waves at radio-frequencies.

Note: The frequency and phase difference between the two lights should be equal. Or the waves should be coherent.
The distance between the slits should be very small. It should be equal to the wavelength of light.
D is the distance of the screen where the pattern will be observed and should not be touched while performing the experiment.