(Multiple choice)

(1) True or False

(a) The virtual image formed by a concave mirror is always smaller than the object.

(b) A concave mirror always forms a virtual image.

(c) A convex mirror never forms a real image of a real object.

(d) A concave mirror never forms an enlarged real image of an object.

(2)

As an object is moved from a great distance toward the focal point of a concave mirror, the image moves from

(a) A great distance toward the focal point and is always real.

(b) The focal point to a great distance from the mirror and is always real.

(c) The focal point toward the center of curvature of the mirror and is always real.

(d) The focal point to a great distance from the mirror and changes from a real to a virtual image.

(3)

An object is placed 40 cm from a lens of focal length –10 cm. The image is

(a) Real, inverted, and diminished.

(b) Real, inverted, and enlarged.

(c) Virtual, inverted, and diminished.

(d) Virtual, upright, and diminished.

(e) Virtual, upright, and enlarged.

(4)

If a real object is placed just inside the focal point of a converging lens, the image is

(a) Real, inverted, and enlarged.

(b) Virtual, erect, and diminished.

(c) Virtual, erect, and enlarged.

(d) Real, inverted, and diminished.

(5)

Chromatic aberration is a common defect of

(a) Concave and convex lenses.

(b) Concave lenses only.

(c) Concave and convex mirrors.

(d) All lenses and mirrors.

(6) True or false:

(a) Aberrations occur only for real images.

(b) Chromatic aberration does not occur with mirrors.

(7)

If an object is placed 25 cm from the eye of a farsighted person who does not wear corrective lenses, a sharp image is formed

(a) Behind the retina, and the corrective lens should be convex.

(b) Behind the retina, and the corrective lens should be concave.

(c) In front of the retina, and the corrective lens should be convex.

(d) In front of the retina, and the corrective lens should be concave.

(8)

Myopic (nearsighted) persons sometimes claim to see better under water without corrective lenses. Why?

(a) The accommodation of the eye’s lens is better under water.

(b) Refraction at the water–cornea interface is less than at the air–cornea interface.

(c) Refraction at the water–cornea interface is greater than at the air–cornea interface.

(d) No reason; the effect is only an illusion and not really true.

(9)

A nearsighted person who wears corrective lenses would like to examine an object at close distance. Identify the correct statement.

(a) The corrective lenses give an enlarged image and should be worn while examining the object.

(b) The corrective lenses give a reduced image of the object and should be removed.

(c) The corrective lenses result in a magnification of unity; it does not matter whether they are worn or removed.

(10)

The image of a real object formed by a convex mirror

(a) Is always real and inverted.

(b) Is always virtual and enlarged.

(c) May be real.

(d) Is always virtual and diminished.

(11)

The glass of a converging lens has an index of refraction of 1.6. When the lens is in air, its focal length is 30 cm. If immersed in water, its focal length will be

(a) Greater than 30 cm.

(b) Less than 30 cm.

(c) The same as before, 30 cm.

(d) Negative.

(12) True or false:

(a) A virtual image cannot be displayed on a screen.

(b) A negative image distance implies that the image is virtual.

(c) All rays parallel to the axis of a spherical mirror are reflected through a single point.

(d) A diverging lens cannot form a real image from a real object.

(e) The image distance for a positive lens is always positive.