Concepts Of Physics MCQ Edition [Volume 1]PhysicsLight Waves
If the light source utilized in a Young's double slit experiment is changed from red to violet,
Options
- Athe fringes will become brighter
- Bconsecutive fringes will come closer together
- Cthe central bright fringe will turn into a dark fringe
- Dthe intensity of the minima will increase
Correct answer
B. consecutive fringes will come closer together
Step-by-step solution
The fringe width in Young's double slit experiment is given by = D d , where is the wavelength of the light used, D is the distance between the slits and the screen, and d is the distance between the two slits. The wavelength of red light is greater than the wavelength of violet light ( _ red > _ violet ). Since the fringe width is directly proportional to the wavelength ( ), decreasing the wavelength by changing the light from red to violet will decrease the fringe width. Therefore, the consecutive fringes will co