Understanding Lenses and Light

What is the action of a thin converging lens on a parallel beam of light?

• The lens disperses the parallel beam of light outward.

• The lens converges the parallel beam of light to a focal point.

• The lens reflects the parallel beam of light away.

• The lens absorbs the parallel beam of light completely.

What is the action of a thin diverging lens on a parallel beam of light?

• The lens has no effect on the parallel beam of light.

• The lens reflects the parallel beam of light.

• The lens causes the parallel beam of light to focus.

• The lens causes the parallel beam of light to diverge.

Define the term 'focal length' in relation to lenses.

• The focal length of a lens is the distance from the lens to the focal point, where parallel rays of light converge.

• The focal length is the distance between two lenses in a system.

• Focal length refers to the diameter of the lens.

• The focal length is the thickness of the lens.

The principal axis of a lens is the line that passes through its center and is perpendicular to its surfaces.

(a)  

• The principal axis is the curved li
• The principal axis is the line that
• The principal axis of a lens is the
• The principal axis is the line that

What is the principal focus (focal point) of a lens?

• The principal focus of a lens is the point where parallel rays of light converge or appear to diverge.

• The principal focus is the point where light rays are completely blocked by the lens.

• The principal focus is the point where light is absorbed by the lens.

• The principal focus is the center of the lens where it is thickest.

Draw a ray diagram to show the formation of a real image by a converging lens. The ray diagram shows a (a)   image formed on the opposite side of the lens, inverted and smaller than the object.

• The ray diagram shows a real image
• The ray diagram depicts a real imag
• The ray diagram shows a virtual ima
• The ray diagram indicates no image

What are the characteristics of a real image formed by a converging lens?

• Upright and virtual

• Inverted, real, and size varies with object distance.

• Only formed at a fixed distance

• Always the same size

A virtual image cannot be projected and is upright; a real image can be projected and is inverted.

(a)  

• A virtual image is formed by conver
• A virtual image is always larger th
• A virtual image can be projected an
• A virtual image cannot be projected

Explain how a virtual image is formed by a diverging lens.

• A virtual image is formed by a diverging lens when it magnifies the object without altering the light rays.

• A virtual image is formed by a diverging lens when light rays diverge after passing through the lens, making them appear to originate from a point behind the lens.

• A virtual image is formed by a diverging lens when light rays converge at a point in front of the lens.

• A virtual image is created by a diverging lens when it reflects light rays back towards the object.

Draw a ray diagram to show the formation of a virtual image by a converging lens.

• The ray diagram shows a virtual image formed by a converging lens when the object is placed at the focal point.

• The ray diagram shows a virtual image formed by a converging lens when the object is placed between the lens and its focal point.

• The ray diagram shows a real image formed by a converging lens when the object is beyond the focal point.

• The ray diagram shows a virtual image formed by a diverging lens when the object is placed at infinity.