Why can’t two independent monochromatic sources of light emitting light of one and the same wavelength behave as coherent sources?

A monochromatic source of light operating at 200W emits 4 xx 10^20 photons per second. Find the wavelength of the light.

What is meant by coherent sources of light?

As a result of interference of two coherent sources of light, energy is

Two coherent source of light can be obtained by

Four monochromatic and coherent sources of light, emitting waves in phase of wavelength lambda , are placed at the points x = 0, d 2d and 3d on the x-axis. Then

When monochromatic light travels from one medium to another, its wavelength changes, but its frequency remains the same. Why ?

Answer the following: (a) what are coherent sources of light ? Two slits in Young's double slit experiments are illuminated by two different sodium lamps emitting light of the same wavelength. Why is no interference pattern observed? (b) Obtain the condition for getting dark and bright fringes in Young's experiment. Hence write the expression for the fringe width. (c) If s is the size of the source and its distance from the plane of the two slits, what should be the criterion for the interference fringes to be seen?

Two coherent sources are 0.18 mm apart and the fringes are observed on a screen 80 cm away. It is found that with a certain monochromatic source of light, the fourth bright fringe is situated at a distance of 10.8 mm from the central fringe. Calculate the wavelength of light.

In young's double slit experiment, the screen is kept 1.6m from the slits. The coherent sources are 0.032 cm apart and fringes are observed on the screen. It is found that with a certain monochromatic source of light, the fourth bright fringe is situated at a distance of 1.06 cm from the central fringe. The wavelength of the light used is

Two incoherent sources of light emitting light of intensity I_(0) and 3I_(0) interfere in a medium. Calculate, the resultant intensity at any point.