Quiz on Thin Converging Lenses

What is the primary action of a converging (convex) lens?

• Dispersing light rays
• Reflecting light rays
• Refracting rays to collect them at a point
• Absorbing light rays

What is the optical center of a lens?

• The point where light enters the lens
• The point at the center of the lens
• The point where light exits the lens
• The point where the lens is thickest

What is the principal axis of a lens?

• The line passing through the optical center perpendicular to the lens surface
• The curve of the lens surface
• The diameter of the lens
• The line connecting the two principal foci

What is the principal focus of a converging lens?

• The point where the lens is thickest
• The point where parallel rays converge after refraction
• The point where the lens touches its mount
• The point where light enters the lens

How is the focal length of a lens defined?

• The diameter of the lens
• The thickness of the lens at its center
• The distance between the principal focus and the optical center
• The total path length of light through the lens

How many principal foci does a thin converging lens have?

• One
• Two
• Three
• Four

What happens to a ray of light passing through the optical center of a lens?

• It is reflected back
• It passes straight through without deviation
• It is refracted at a 90° angle
• It splits into multiple rays

What happens to a ray of light passing parallel to the principal axis of a converging lens?

• It passes straight through
• It is reflected back
• It is refracted through the principal focus
• It exits the lens at a 45° angle

What happens to a ray of light passing through the principal focus of a converging lens?

• It is absorbed by the lens
• It is refracted parallel to the principal axis
• It is reflected back
• It exits the lens at a random angle

Which of the following is NOT a key property of a converging lens?

• It has a positive focal length
• It is thicker at the edges than at the center
• It can form both real and virtual images
• It can magnify objects