Describe the image shown above of an object placed at 2F.

A. The image is inverted, virtual and same size as the object.
Incorrect. The image is real, because it can be projected onto a screen.

B. The image is upright, virtual and same size as the object.
Incorrect. Careful. The image is inverted and it is real (can be projected onto a screen).

C. The image is inverted, real and larger than the object.
Incorrect. Careful. The image is inverted, it is real (can be projected onto a screen) but it is the same size as the object at 2F.

D. The image is inverted, real and same size as the object.
Correct! The image is the same size as the object, it is a virtual image (can be projected onto a screen) and it is inverted (upside down.)

Convex lenses, also known as converging lenses form —

A. virtual images and real images
Correct! Depending upon the position of the object, the images formed can be virtual (cannot be projected onto a screen) or real (can be projected onto a screen).

B. virtual images but no real images
Incorrect. Depending upon the position of the object, the images formed can be virtual (cannot be projected onto a screen) or real (can be projected onto a screen).

C. real images but no virtual images
Incorrect. Depending upon the position of the object, the images formed can be virtual (cannot be projected onto a screen) or real (can be projected onto a screen).

D. neither virtual nor real images
Incorrect. Depending upon the position of the object, the images formed can be virtual (cannot be projected onto a screen) or real (can be projected onto a screen).

If an object is placed at one focus of a convex lens, describe the image formed by the lens.

A. The image is formed at F, it is the same size and it is inverted and real.
Incorrect. No image is formed when an object is placed at F of the convex lens.

B. The image is formed at F, it is the same size and it is upright and real.
Incorrect. No image is formed when an object is placed at F of the convex lens.

C. The image is formed at F, it is the same size and its is inverted and virtual.
Incorrect. No image is formed when an object is placed at F of the convex lens.

D. No image is formed.
Correct! No image is formed when an object is placed at the focus of a convex lens. The rays travel parallel to each other and neither converge nor diverge.

A convex lens is described as a lens that is —

A. converging, with the center thinner than the edges if viewed from the side
Incorrect. The convex lens is converging, but its center is thicker than its edges if viewed from the side.

B. diverging, with the center thinner than the edges if viewed from the side
Incorrect. The convex lens is converging!

C. converging, with the center thicker than the edges if viewed from the side
Correct! The convex lens is converging, and it is thicker at the center than the edges if viewed from the side.

D. diverging, with the center thicker than the edges if viewed from the side
Incorrect. The convex lens is converging!