Optics Practice — Reflection, Refraction and Lenses
10 problems · instant feedback · full explanations
Optics is geometry with light. Draw the rays, mark the angles from the normal (not the surface!), and let Snell's law and the lens equation handle the numbers.
Q1.
What is the law of reflection?
Multiple choice · Easy
Q2.
A light ray strikes a mirror at 30° to the normal. At what angle to the normal does it reflect?
Numerical answer (°) · Easy
Q3.
Light travels from air (n = 1.00) into water (n = 1.33) at 45° to the normal. What is the angle of refraction?
Numerical answer (°) · Medium
Q4.
A ray passes from water into air. How does it bend at the boundary?
Multiple choice · Medium
Q5.
An object is placed 30 cm from a converging lens of focal length 10 cm. Where is the image formed?
Numerical answer (cm) · Medium
Q6.
True or false: a convex lens can form a real image.
True / False · Easy
Q7.
Which condition produces total internal reflection?
Multiple choice · Medium
Q8.
An object is 60 cm in front of a concave mirror of focal length 20 cm. Where is the image?
Numerical answer (cm) · Hard
Q9.
What is the critical angle for light going from water (n = 1.33) to air?
Multiple choice · Hard
Q10.
True or false: light travels faster in glass than in air.
True / False · Easy