Concept Items

Part A. Can you see a virtual image? Part B. Can you photograph one? Explain your answers.

1. A. yes; B. No, an image from a flat mirror cannot be photographed.
2. A. no; B. Yes, an image from a flat mirror can be photographed.
3. A. yes; B. Yes, an image from a flat mirror can be photographed.
4. A. no; B. No, an image from a flat mirror cannot be photographed.

State the law of reflection.

1. ${\vartheta }_r={\vartheta }_i$, where ${\vartheta }_r$ is the angle of reflection and ${\vartheta }_i$ is the angle of incidence.
2. ${\vartheta }_r>{\vartheta }_i$, where ${\vartheta }_r$ is the angle of reflection and ${\vartheta }_i$ is the angle of incidence.
3. ${\vartheta }_r<{\vartheta }_i$, where ${\vartheta }_r$ is the angle of reflection and ${\vartheta }_i$ is the angle of incidence.
4. ${\vartheta }_r=0$, where ${\vartheta }_r$ is the angle of reflection.

An object is positioned in front of a lens with its base resting on the principal axis. Describe two rays that could be traced from the top of the object and through the lens that would locate the top of an image.

1. A ray perpendicular to the axis and a ray through the center of the lens
2. A ray parallel to the axis and a ray that does not pass through the center of the lens
3. A ray parallel to the axis and a ray through the center of the lens
4. A ray parallel to the axis and a ray that does not pass through the focal point

For a concave lens, if the image distance, d_i, is negative, where does the image appear to be with respect to the object?

1. The image always appears on the same side of the lens.
2. The image appears on the opposite side of the lens.
3. The image appears on the opposite side of the lens only if the object distance is greater than the focal length.
4. The image appears on the same side of the lens only if the object distance is less than the focal length.