Optics is the branch of physics that deals with the study of light, its behaviour, properties and phenomena such as reflection, refraction and image formation.
Light is a form of energy which enables us to see objects.
Light shows both wave nature and particle nature. In basic optics, light is mainly treated as a ray.
A ray of light is the straight-line path along which light energy travels.
A group of light rays travelling together is called a beam of light.
The speed of light in vacuum is approximately 3 × 108 m s−1.
Q1. Optics is the study of: A) Sound B) Heat C) Light D) Electricity Answer: C Q2. Light travels in the form of: A) Curved paths B) Random paths C) Straight lines D) Circular paths Answer: C Q3. A ray of light represents: A) A beam of light B) Path of light energy C) Source of light D) Reflection only Answer: B Q4. Speed of light in vacuum is approximately: A) 3 × 10^6 m/s B) 3 × 10^7 m/s C) 3 × 10^8 m/s D) 3 × 10^9 m/s Answer: C Q5. Which of the following is a beam of light? A) Single ray B) Group of rays C) Image D) Shadow Answer: B
Branch of physics dealing with study of light.
Straight-line path of light.
Group of light rays.
3 × 108 m s−1 (in vacuum)
Direct MCQs are asked on definition of optics, ray, beam and speed of light.
