Lenses and Ray Diagrams

Question

The orientation and magnification of an image depend on the object's position in relation to the focal point and the lens. In a convex lens, if an object is closer to the lens than the focal point, a virtual image forms. If the object is farther from the lens than the focal point, a real image forms. A concave lens always forms an image that is virtual, right side up, and smaller than the actual image.

Real Image Virtual Image
Image is inverted
Rays of light actually meet
Forms below principal axis
Image is upright
Rays of light appear to meet
Forms above principal axis
The image that forms when an object is outside the focal point in a convex and concave lens is shown.

Two incomplete models show the object inside the focal point of a convex and concave lens.

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Two-Part Question
Multiple Choice Question
The following question has two parts. First, answer Part A. Then, answer Part B.

Part A:

Which choice shows the completed ray diagram for Model 2?

A.

B.

C.

D.

Multiple Choice Question
Part B:

Which BEST describes the image from the choice in Part A?

A.
The image is upright and larger.

B.
The image is upright and smaller.

C.
The image is upside down and larger.

D.
The image is upside down and smaller.

Answer 1

To address the two-part question regarding ray diagrams and images formed by lenses, let’s clarify how each type of lens behaves based on the object’s position relative to the focal point.

Part A:

For a convex lens when the object is located inside the focal point, a virtual image is produced. This virtual image is formed on the same side as the object and can be represented in the ray diagram as follows:

• The diagram shows rays diverging from the object, and the extended rays behind the lens appear to converge at a point above the principal axis, indicating the location of the virtual image.

For a concave lens, the behavior is slightly different, but when the object is inside the focal point, the image too will be virtual, located on the same side of the lens as the object, but smaller and upright.

Assuming Model 2 refers to the convex lens scenario and the choices A-D represent completed ray diagrams, the completed ray diagram for Model 2 (the convex lens with the object inside the focal point) would show:

• Two rays from the object: one would pass straight through the center of the lens, and another would diverge, which when extended backward, would appear to come from a point (the virtual image) located above the principal axis.

Since I can't view the specific diagrams (A-D), you will need to identify which one matches this description.

Part B:

Referring to the characteristics of the image formed by the convex lens when the object is inside the focal point:

1. Upright: The image formed is always upright.
2. Larger: The image is larger than the original object since it’s formed when looking through the lens from the same side.

Therefore, the best description based on the qualities of this virtual image would be:

A. The image is upright and larger.

Again, you would choose the specific diagram in Part A based on this understanding of lenses and ray diagrams.