(a) Define a wavefront. Using Huygen's principle, verify the laws of reflection at a plane surface. (b) In a single-slit diffraction experiment, the width of the slit is made double the original width. How does this affect the size and intensity of the central diffraction band? Explain. (c) When a tiny circular obstacle is placed in the path of light from a distant source, a bright spot is seen at the centre of the obstacle. explain why.

Define a wavefront. Using Huygen's principle, verifyi the laws of reflection at a plane surface.

Define a wavefront. Use huygen's principle to verify the laws of defraction.

Using Huygens' principle, establish the law of reflection.

Wavefront and Huygens principle

Define wavefront of a travelling wave. Using Huygens principle, obtain the law of refraction at a plane interface when light passes from rarer to a denser medium.

(a) Define wevefront. Use Huygens 'principle to verify the laws of refraction . (b) How is linearly polarised light obtained by the process of scattering of light ? Find the Brawster angle for air- glass interface, when the refractive index of glass = 1.5

State Huygens' principle and prove the laws of reflection on the basis of wave theory.