# Lesson Worksheet: Convex Lenses Physics • 9th Grade

In this worksheet, we will practice defining a convex lens, describing the paths of light rays refracted through it, and explaining how rays are focused by such lenses.

Q1:

Which of the objects shown in the diagram is a convex lens? • A(C)
• B(D)
• C(B)
• D(A)
• E(E)

Q2:

Light rays diverging from a point are incident on a convex lens, as shown in the diagram. Which of the other diagrams, (A), (B), (C), and (D), most correctly shows the directions of the rays that exit the lens? • A(A)
• B(B)
• C(D)
• D(C)

Q3:

Part of a convex lens is shown. No light rays pass through the lens, but several possible lines normal to the surface of the lens are shown. Which line on the left-hand side of the lens is normal to the surface at the point that the line contacts the surface?

• BB
• CC
• DA

Which line on the right-hand side of the lens is normal to the surface at the point that the line contacts the surface?

• AE
• BF
• CG
• DH

Q4:

At which of the points A, B, C, D, and E shown in the diagram is the angle of refraction greatest? • AE
• BB
• CD
• DA
• EC

Q5:

The two convex lenses shown have different focusing powers.

Which is the more powerful lens?

• ALens A
• BThey have the same power.
• CLens B

How many times is the more powerful lens more powerful?

Q6:

Which of the following diagrams correctly shows the paths of light rays exiting a convex lens if the light rays enter the lens parallel to each other but at an angle to the axis of the lens, as shown in the diagram? • A(d)
• B(c)
• C(a)
• D(b)

Q7:

Which of the following statements correctly describes a convex lens?

• AA convex lens is thicker than a concave lens.
• BA convex lens has uniform thickness.
• CA convex lens increases in thickness from its center to its edges.
• DA convex lens decreases in thickness from its center to its edges.

Q8:

A simple refracting telescope consists of two convex lenses of different focal lengths that are aligned along the same axis, as shown in the diagram. Which of the two lenses is more powerful?

• AThe objective lens is more powerful than the eyepiece lens.
• BThe eyepiece lens is more powerful than the objective lens.
• CThe eyepiece and objective lenses are equally powerful.

Which of the following statements most correctly describes the effect of a simple refracting telescope on the light that passes through it?

• AThe telescope makes parallel light rays from an object further apart from each other.
• BThe light rays coming from the eyepiece lens are brought to a focal point.
• CThe telescope produces an image that is larger than the imaged object.
• DThe telescope makes parallel light rays from an object closer to each other.

Q9:

Parallel light rays fall on the object shown in the diagram. Which of the other diagrams (a), (b), (c), and (d) correctly shows how the rays move through and out of the object?  • A(b)
• B(d)
• C(c)
• D(a)

Q10:

Which of the following diagrams correctly shows the paths of light rays exiting a convex lens if the light rays enter the lens parallel to the axis of the lens?

• A(c)
• B(e)
• C(b)
• D(a)
• E(d)