With reference to Young’s double slit experiment, explain how interference pattern is formed.
With reference to Young’s double slit experiment,
(i) explain how interference pattern is formed.
When two coherent waves travel in a medium, they meat and superimpose.
Where they meet in phase, constructive interference takes place and intensity is increased (or maximum)
Where they meet out of phase, cancellation takes place and intensity reduces (minimum)
Patterns of alternative regions of maximum and minimum intensities are formed that form interference pattern.
(ii) State what happens to the fringes when the source of light is moved nearer to the slits.
The intensity of fringes increase
(iii) state what happens to fringes when the separation of slits is changes
increase in separation of slits reduces fringe separation.
(iv) describe the appearance of fringes when white light is used
When white light is used, colored fringes are observed. The central fringe is white, followed by blue and red fringes further off. Outwards the color overlap leading to white illumination
