Interference | Old is Gold | Class XII



Interference

Short Answer Questions
1. Can two independent sources of light produce interference?

2. Why have the two sources of light to be close to each other for the production of good interference pattern?

3. Distinguish between interference and diffraction. What do you understand by coherent sources?

4. In young’s double slit experiment, how is the fringe width altered if the separation between the slits is doubled and the distance between the slits and the screen is halved?

5. What are the conditions for sustained interference of light?

6. In Young’s double slit experiment, how is the fringe width altered if the separation between the slits is doubled and the distance between the slits and the screen is halved?

7. What do you understand by the coherent sources of light?

Long Answer Questions

1. Derive the fringe width from Young’s double slit experiment.

2. What do you understand by interference of light? Derive an expression for the fringe width in a Young’s double slits experiment.

3. Describe Young’s double slits experiment for the interference of light and show that widths of bright and dark fringes are the same.

4. Prove analytically that the bright and dark fringes in young’s double slit experiment are equally spaced.

5. Draw a clear ray diagram to illustrate the action of a compound microscope. Also derive an expression for its magnifying power.

6. Describe Young’s double slit experiment, if brief, for the measurement of wave=length of a monochromatic source of light.

7. Where is the near point of an eye for which a spectacle lens of power +2D is prescribed?