Pre-lecture Questions

Which of the following statements are true for images formed by thin lenses: A diverging lens always produces a virtual image of an object placed in front of it. A diverging lens always produces an upright image of an object placed in front of it. A converging lens always produces an inverted image of an object placed in front of it. A converging lens always produces a real image of an object placed in front of it. A diverging lens always produces an image that is larger than the object. A converging lens always produces an image that is larger than the object.

A ray of light passes from air into a block of clear plastic. How does the angle of incidence in the air compare to the angle of refraction in the plastic?

Suppose a ray of light traveling in a material with an index of refraction na reaches an interface with a material having an index of refraction nb. Which of the following statements must be true for total internal reflection to occur? na > nb The angle of incidence must be equal to the critical angle. na = nb The angle of incidence must be greater than the critical angle. The angle of incidence must be less than the critical angle.

Which of the following statements are true concerning the eye? The far point of the normal eye is infinity. Astigmatism refers to a defect in which the surface of the cornea is not spherical. Instead, it is more sharply curved in one plane than another. Farsightedness can be corrected with a diverging lens. Nearsightedness can be corrected with a diverging lens. The hyperopic eye focuses rays from an object at infinity in front of the retina; the myopic eye focuses rays from an object at infinity behind the retina.

A ray of light crosses a boundary between two transparent materials. The medium the ray enters has a larger index of refraction. Which of the following statements are true? The frequency of the light remains constant as it transitions between materials. The wavelength of the light remains constant as it transitions between materials. The wavelength of the light decreases as it enters into the medium with the greater index of refraction. The speed of the light remains constant as it transitions between materials. The speed of the light increases as it enters the medium with the greater index of refraction. The frequency of the light decreases as it enters into the medium with the greater index of refraction.

Which of the following statements are true for an image formed by a plane mirror when the object is placed in front of the mirror? The image formed by a plane mirror is always an upright image. The image is always larger than the object. The image formed by a plane mirror is always a virtual image. The image always appears to be located the same distance behind the mirror as the object is located in front of the mirror. The image formed by a plane mirror is always an inverted image. The image formed by a plane mirror is always a real image.

Which of the following statements are true concerning the reflection of light? For diffuse reflection, the angle of incidence is greater than the angle of reflection. The reflection of light from a rough surface is called diffuse reflection. The reflection of light from a smooth surface is called specular reflection. The angle of incidence is equal to the angle of reflection only when a ray of light strikes a plane mirror. For specular reflection, the angle of incidence is less than the angle of reflection.

Which of the following statements are true for images formed by spherical mirrors? A concave mirror always produces an inverted image on an object placed in front of it. A convex mirror always produces an image that is the same size as the object. A concave mirror always produces an image that is the same size as the object. A concave mirror always produces a real image of an object placed in front of it. A convex mirror always produces an upright image of an object placed in front of it. A convex mirror always produces a virtual image of an object placed in front of it.

Which of the following statements are true concerning compound microscopes? In a compound microscope, the image formed by the objective lens is a real image. In a compound microscope, the final image is formed by the objective lens. In a compound microscope, the final image is a virtual image. The focal length of the objective in a microscope is very large compared to the focal length of the eyepiece. In a compound microscope, the image formed by the objective lens is smaller than the object.

When glasses (or contact lenses) are used to correct nearsightedness, where should the corrective lens form an image of an object located at infinity in order for the eye to form a clear image of that object?

When glasses (or contact lenses) are used to correct farsightedness, where should the corrective lens form an image of an object located between the eye and the near point in order for the eye to form a clear image of that object?

To a swimmer under water, objects look blurry. When goggles are worn, however, the images are sharp. Why is this so?