Convex & Concave Lenses Flashcards

All 7 cards in this deck

How does a lens form an image?

By refracting light.

What is the principal focus of a convex lens?

The point where rays of light parallel to the axis are brought to a focus after passing through the lens.

What is the focal length of a lens?

The distance from the lens to the principal focus.

What is the ray diagram symbol for a convex lens and for a concave lens?

Convex: a vertical line with arrowheads pointing outwards at each end.
Concave: a vertical line with arrowheads pointing inwards at each end.

What does a concave lens do to rays of light that are parallel to the axis?

It makes them diverge, so they appear to come from the principal focus on the same side as the object.

True or false? The image produced by a concave lens is always virtual.

True. A concave lens diverges light, so the image is always virtual (and upright and diminished).

True or false? A convex lens can only produce a real image.

False. A convex lens produces a real image or a virtual image, depending on where the object is placed.