Concave lenses

What is a concave lens?

• A lens that is thicker in the center than at the edges.

• A lens that is thicker at the edges than in the center.

• A lens that focuses parallel light rays to a point.

• A lens that makes light rays converge.

How do concave lenses affect parallel light rays?

• They focus them to a single point.

• They make them converge.

• They make them spread out.

• They reflect them back.

What is true about the principal focus of a concave lens?

• It is where light rays actually cross after passing through the lens.

• It is the point where parallel light rays appear to originate from after passing through the lens.

• It is the point where the image is always formed.

• It is the center of the lens.

What is the first step when drawing a ray diagram to show an image formed by a concave lens?

• Draw a ray from the top of the object parallel to the principal axis.

• Draw a ray from the top of the object passing through the principal focus.

• Draw a ray from the top of the object passing through the center of the lens without changing direction.

• Draw a ray from the bottom of the object to the principal focus.

What are the properties of an image formed by a concave lens?

• Magnified, inverted, real.

• Diminished, right way up, virtual.

• Magnified, right way up, virtual.

• Diminished, inverted, real.