Geometric OpticsConceptual MC Questions

If the image distance is positive, the image formed is a

(A) real image.

(B) virtual image.

If the image distance is negative, the image formed is a

(A) real image.

(B) virtual image.

If the magnification is a positive value, the image is

(A) upright.

(B) inverted.

If the magnification is a negative value, the image is

(A) upright.

(B) inverted.

If the absolute value of the magnification is larger than one, then the image is

(A) larger than the object.

(B) the same size as the object.

(C) smaller than the object.

If the absolute value of the magnification is smaller than one, then the image is

(A) larger than the object.

(B) the same size as the object.

(C) smaller than the object.

If the absolute value of the magnification is equal to one, then the image is

(A) larger than the object.

(B) the same size as the object.

(C) smaller than the object.

For all transparent material substances, the index of refraction

(A) is less than 1.

(B) is greater than 1.

(C) is equal to 1.

(D) could be any of the given answers; it all depends on optical density.

An index of refraction less than one for a medium would imply

(A) that the speed of light in the medium is the same as the speed of light in vacuum.

(B) that the speed of light in the medium is greater than the speed of light in vacuum.

(C) refraction is not possible.

(D) reflection is not possible.

The index of refraction of diamond is 2.42. This means that a given frequency of light travels

(A) 2.42 times faster in air than it does in diamond.

(B) 2.42 times faster in diamond than it does in air.

(C) 2.42 times faster in vacuum than it does in diamond.

(D) 2.42 times faster in diamond than it does in vacuum.

The angle of incidence

(A) must equal the angle of refraction.

(B) is always less than the angle of refraction.

(C) is always greater than the angle of refraction.

(D) may be greater than, less than, or equal to the angle of refraction.

Light traveling at an angle into a denser medium is refracted

(A) toward the normal.

(B) away from the normal.

(C) parallel to the normal.

(D) equally.

Light enters air from water. The angle of refraction will be

(A) greater than the angle of incidence.

(B) equal to the angle of incidence.

(C) less than the angle of incidence.

A ray of light, which is traveling in air, is incident on a glass plate at a 45° angle. The angle of refraction in the glass

(A) is less than 45°.

(B) is greater than 45°.

(C) is equal to 45°.

(D) could be any of the above; it all depends on the index of refraction of glass.

The principle on which fiber optics is based is

(A) refraction.

(B) polarization.

(C) dispersion.

(D) total internal reflection.

The critical angle for a beam of light passing from water into air is 48.8°. This means that all light rays with an angle of incidence greater than this angle will be

(A) absorbed.

(B) totally reflected.

(C) partially reflected and partially transmitted.

(D) totally transmitted.

The principle on which lenses work is

(A) refraction.

(B) polarization.

(C) dispersion.

(D) total internal reflection.

Lenses that are thickest at the center called

(A) converging lenses.

(B) diverging lenses.

Lenses that are thinner at the center than the edges are called

(A) converging lenses.

(B) diverging lenses.

Lenses that are thicker at the center

(A) spread out light rays.

(B) bend light rays to a point beyond the lens.

(C) have no effect on light rays.

(D) reflect light rays back.

A light ray, traveling parallel to the axis of a convex thin lens, strikes the lens near its midpoint. After traveling through the lens, this ray emerges traveling obliquely to the axis of the lens

(A) such that it never crosses the axis.

(B) crossing the axis at a point equal to twice the focal length.

(C) passing between the lens and its focal point.

(D) passing through its focal point.

A convex lens has focal length f. An object is located at infinity. The image formed is located

(A) at 2f.

(B) between f and 2f.

(C) at f.

(D) between the lens and f.

A convex lens has a focal length f. An object is placed at f on the axis. The image formed is located

(A) at infinity.

(B) between 2f and infinity.

(C) at 2f.

(D) between f and 2f.

A convex lens has focal length f. An object is placed at 2f on the axis. The image formed is located

(A) at 2f.

(B) between f and 2f.

(C) at f.

(D) between the lens and f.

A convex lens has a focal length f. An object is placed between f and 2f on the axis. The image formed is located

(A) at 2f.

(B) between f and 2f.

(C) at f.

(D) at a distance greater than 2f from the lens.

A convex lens has a focal length f. An object is placed between infinity and 2f from the lens on its axis. The image formed is located

(A) at 2f.

(B) between f and 2f.

(C) at f.

(D) between the lens and f. 23.7-23.8

A object is placed between a convex lens and its focal point. The image formed is

(A) virtual and erect.

(B) virtual and inverted.

(C) real and erect.

(D) real and inverted.

The images formed by concave lenses

(A) are always real.

(B) are always virtual.

(C) could be real or virtual; it depends on whether the object distance is smaller or greater than the focal length.

(D) could be real or virtual, but always real when the object is placed at the focal point.