SINGLE SLIT DIFFRACTION - Q9

9) What is the source you are using in your experiment? How does it work?
Ans: Laser, He-Ne 1.0 mw is used as source in the experiment. A helium–neon laser or He-Ne laser is a type of gas laser whose gain medium consists of a mixture of helium and neon inside of a small bore capillary tube, usually excited by a DC electrical discharge. It uses mechanism of population inversion and light amplification.

SINGLE SLIT DIFFRACTION - Q8

8) What is the difference between a single slit and double slit fringe systems?
Ans: Single slit pattern has a central maximum; and minima on either side at angles satisfying the condition bsinθ = mλ (m ≠ 0). On the other hand, the double slit diffraction pattern is a mix of interference and diffraction patterns.

SINGLE SLIT DIFFRACTION - Q7

7) What will happen if the width of the slit is increased?
Ans: Intensity of diffraction pattern increases. Fringe width decreases. Diffraction pattern resolution will be less.

SINGLE SLIT DIFFRACTION - Q6

6) In present experiment what kind of diffraction occurs and how?
Ans: Fraunhofer diffraction occurs in this experiment.

The light rays from the source are made parallel using lenses in the laser. Now, optically source and screen are at very large distance. Clearly, plane wave fronts strike the slit. So, Fraunhofer diffraction occurs in this experiment.

SINGLE SLIT DIFFRACTION - Q5

5) Distinguish between Fresnel and Fraunhofer diffraction.
Ans: 

SINGLE SLIT DIFFRACTION - Q4

4) How many classes of diffraction are there?
Ans: Diffraction of light can be divided into two classes.

• Fraunhofer diffraction
• Fresnel diffraction

SINGLE SLIT DIFFRACTION - Q3

3) When does the diffraction become appreciable?
Ans: Diffraction becomes appreciable if opening is comparable to the wavelength of light incident. If the opening is much larger than the light's wavelength, the bending will be almost unnoticeable.

SINGLE SLIT DIFFRACTION - Q2

2) How does diffraction differ from interference?
Ans: Diffraction is the bending of waves around an obstacle, while interference is the superposition of two waves. In interference, waves emitted from two coherent sources get superposed while; in diffraction the waves emitted from different points of a limited part of the same wave front get superposed.

SINGLE SLIT DIFFRACTION - Q1

1) What do you understand by diffraction of light?
Ans: Diffraction is the slight bending of light as it passes around the edge of an object. The amount of bending depends on the relative size of the wavelength of light to the size of the opening. If the opening is much larger than the light's wavelength, the bending will be almost unnoticeable. When the wave front of a light ray is partially obstructed, only those wavelets which belong to the exposed parts superpose, in such a way that the resulting wave front has a different shape. This permits bending of light around the edges.