Chapter No.6 Introduction to Diffraction

All exercise Short Questions of Introduction to Diffraction of book Optics for BS/MSc Physics students.

Q.1 State the Hygen principle for plane and spherical wavefronts.

Answer: Hygen’s principle states that,

1. Every point on the wavefront will cause the source of the secondary wavelets.
2. The new position of the wavefronts is achieved by drawing or joining the all tangents.

Q.2 Differentiate between Fresnel and Fraunhoffer diffraction.

Answer: Reference Book Optics by Quanta Publishers, Chapter: Introduction to Diffraction, 1^st edition page 150

Q.3 What is the relation between power and focal length?

Answer:  The relation is $P=\frac{1}{f}$  (unit is diopter)

Q.4 What are the types of abbrations and how they are removed?

Answer: Reference Book Optics by Quanta Publishers, Chapter: Introduction to Optics, 1^st edition page 14 (Topic: 1.4)

Q.5 Differentiate between ray and beam.

Answer; A normal line drawn on wavefronts is called ray and beam is the light travelling along straight path from source.