12 - THIN LENSES

Question 1

are thicker at the center than at the rim and converge a beam of parallel light to a real focus.

Answer 1

Converging lenses

Question 2

are thinner at the center than at the rim and diverge a beam of parallel light from a virtual focus.

Answer 2

Diverging lenses

Question 3

The __________ of a thin lens with spherical surfaces is the point F where rays parallel to and near the principal axis x are brought to a focus; this focus is ________ for converging lens and virtual for a diverging lens.

Answer 3

principal focus
real

Question 4

The ___________ is the distance of the principal focus from the lens.

Answer 4

focal length

Question 5

Given an upright and real object, a _______________ form a real and inverted image of an object located outside of the principal focus.

For an object located inside the principal focus, the image is __________ (on the same side of the lens as the object), _________, and ________.

Answer 5

converging lens

virtual, upright and enlarged

Question 6

With the same object, a __________ produces only virtual, upright and smaller image.

Answer 6

diverging lens