Lenses Introduction

The ray diagram shows two rays from a point on an object placed in front of a diverging lens.What are the properties of the image produced?

• Real and larger than the object

• Real and smaller than the object

• Virtual and larger than the object

• Virtual and smaller than the object

A student starts to draw a ray diagram for an object at O, near a thin convex lens, but is not sure whether the image is formed at O or at F.The correctly drawn image is

• virtual and formed at X

• virtual and formed at F

• real and formed at X

• real and formed at F

The diagram shows rays of light passing through a converging lens. Which labelled arrow represents the focal length of the lens?

• A

• B

• C

• D

The image formed by a concave lens is always

• virtual and inverted

• virtual and upright

• real and inverted

• real and upright

A convex lens has focal length f. If an object is located very far away from the lens, the image will be formed at a distance _______from the lens.

• f

• 2f

• between f and 2f

• infinity

What type of lens is wider in the middle than on the edges?

• Concave

• Convex

• Objective

• Ocular

What type of lens is thinner in the middle than at the edges?

• Convex

• Concave

• Objective

• Magnifying

When light passes through a convex lens, it does this.....

• Diverge, or spread apart

• Converge, or come together

• Reflect, or bounce off

• Create a rainbow

Tags

NGSS.MS-PS4-2

Which of the following correctly labels points A, B, and C?

• focal point, focal length, principal axis

• focal point, principal axis, focal length

• principal axis, focal length, focal point

• focal length, focal point, principal axis

The focal length of this lens is _______.

• negative because it can form real images

• positive because it can form real images

• negative because it can form virtual images

• could be positive or negative depending on the image formed