Chapter 26 and 27 Questions

18. Complete the following statement: Fiber optics make use of

A) total internal reflection.

Complete the following sentence: The term coherence relates to

A) the phase relationship between two waves.

Which one of the following statements best explains why the diffraction of sound is more apparent than the diffraction of light under most circumstances?

) The wavelength of light is considerably smaller than the wavelength of sound.

Which one of the following statements is true concerning a magnifying glass?

A) It produces a virtual image.

In a scene from a movie, a nearsighted character removes his eyeglasses and uses them to focus the nearly parallel rays of the sun to start a fire. What is physically wrong with this scene?

A) The eyeglasses have diverging lenses and cannot be used to focus parallel rays.

When an object is placed 25 cm from a lens, a real image is formed. Which one of the following conclusions is incorrect?

A) The image is upright.

The table lists the range of wavelengths in vacuum corresponding to a given color. Which one of these colors will produce a diffraction pattern with the widest central maximum, assuming all other factors are equal?

A) red

A converging lens is used to focus light from a small bulb onto a book. The lens has a focal length of 10.0 cm and is located 40.0 cm from the book. Determine the distance from the lens to the light bulb.

B) 13 cm

Two identical light waves, A and B, are emitted from different sources and meet at a point P. The distance from the source of A to the point P is LA; and the source of B is a distance LB from P. Which one of the following statements is necessarily true concerning the interference of the two waves?

B) A and B will interfere constructively if LA = LB.

When an object is placed 15 cm from a lens, a virtual image is formed. Which one of the following conclusions is incorrect?

B) If the image is upright the lens must be a diverging lens.

Rachel has a far point of 5 m. Which statement below concerning Rachel's vision is true?

B) She is myopic and requires diverging lenses to correct her vision.

A beam of light passes from air into water. Which is necessarily true?

B) The frequency is unchanged and the wavelength decreases.

An object is placed 6.5 cm from a thin converging lens with a focal length of 14 cm. Which one of the following statements is true concerning the image?

B) The image is virtual and 12 cm from the lens.

Red laser light passes through a single slit to form a diffraction pattern. If the width of the slit is increased by a factor of two, what happens to the width of the central maximum? Note: Assume that the angle θ is sufficiently small so that (sin θ) is nearly equal to θ.

B) The width of the central maximum decreases by a factor of 2.

Light that is incident upon the eye is refracted several times before it reaches the retina. As light passes through the eye, at which boundary does the majority of the overall refraction occur?

B) air/cornea

. Complete the following statement: The term dispersion refers to the fact that the index of refraction of certain materials

B) depends on the wavelength of light.

Which physical phenomenon is illustrated by the fact that the prism has different refractive indices for different colors?

B) dispersion

Which pair of terms most accurately describes the image? from 5cm ob placed 35 cm away

B) virtual, upright

The figure is a scaled diagram of an object and a converging lens surrounded by air. Only one focal point, F, of the lens is shown. At which of the labeled points will the image be formed

C) C

Which one of the following statements provides the most convincing evidence that electromagnetic waves have a transverse character?

C) Electromagnetic waves can be polarized

Which one of the following statements is true concerning the focal length of a lens?

C) The focal length is different for different colors because of dispersion

A ray of blue light travels through air and is refracted as it enters a glass prism shown in the figure. An unknown liquid is in contact with the right side of the prism. The light then follows the path shown. Which one of the following statements concerning this situation is true?

C) The index of refraction of the unknown liquid is the same as that of the glass

Which one of the following statements best explains why interference patterns are not usually observed for light from two ordinary light bulbs?

C) The two sources are not coherent.

In a Young's double slit experiment, green light is incident on the two slits. The interference pattern is observed on a screen. Which one of the following changes would cause the fringes to be more closely spaced?

C) Use blue light instead of green light.

What does one observe on the screen in a Young's experiment if white light illuminates the double slit instead of light of a single wavelength?

C) a white central fringe and a series of colored and dark fringes on each side of the center

A diverging lens has a focal length of ñ15 cm. A 5-cm object is placed 35 cm from the lens. Determine the approximate distance between the object and the image.

D) 24 cm

Which one of the following statements provides the most convincing evidence that visible light is a form of electromagnetic radiation?

D) Light can form a double-slit interference pattern.

When an object is placed 20 cm from a diverging lens, a reduced image is formed. Which one of the following statements is necessarily true?

D) The focal length of the lens may be less than 20 cm.

The system is immersed in a fluid other than air that has an index of refraction that is larger than that of the lens. Which one of the following statements is true concerning this new situation?

D) The image will be formed on the same side of the lens as the object

The compound microscope discussed in Cutnell and Johnson's text is made from two lenses. Which one of the following statements is true concerning the operation of this microscop

D) The lens closest to the object forms a real image; the other lens forms a virtual image.

An object is placed at the focal point of a thin diverging lens of focal length f. What is the image distance?

D) f/2

Which physical phenomenon is illustrated by the fact that the observer will not see all three colors of light?

D) total internal reflection

Which one of the following statements best explains why chromatic aberration occurs in lenses, but not in mirrors?

E) Different colors of light are refracted by different amounts as the light passes through a lens.

Which one of the following statements concerning the index of refraction for a given material is true?

E) For a given frequency, the index of refraction is inversely proportional to the wavelength of light in the material.

The index of refraction of this lens is 1.51 for red light and 1.53 for blue light. Blue light is focused at the point F. Which one of the following statements is true concerning the focal point for red light? E) It is to the right of and close to F.

E) It is to the right of and close to F.

An object is placed at the focal point of a converging lens of focal length f. What is the image distance?

E) at an infinite distance

A beam of light that consists of a mixture of red, green and violet light strikes a prism (surrounded by air) as shown. Indices of refraction for this prism for the various colors are indicated in the table. An observer is located to the right of the prism as shown. Which color(s) could, in principle, be seen by the observer?

E) only green and violet light

Which physical phenomenon is illustrated by the fact that the emerging rays are spread into the component colors of the beam?

dispersion

Which pair of terms most accurately describes the image?

real, inverted