GenPhys2 Q4W4: Geometric Optics

What happens to the image produced by a pinhole camera when you move the back wallfarther from the pinhole? It becomes ____.

• larger and fainter

• smaller and fainter

• larger and brighter

• smaller and brighter

A ray of light parallel to the optic axis of a concave mirror is reflected back

• through the center of the sphere.

• through the focal point.

• parallel to the optic axis.

• as if it came from the focal point.

The back surfaces of automobile/motorcycle headlights are curved

• because inverted, real images of filaments shine brighter.

• to concentrate light in one direction.

• for structural reasons not related to optics

• to get multiple images of the filament.

What type of image is formed when an object is placed at a distance of 1.5 focal lengths from a convex mirror?

• erect and virtual

• inverted and virtual

• erect and real

• inverted and real

Where is the image located when an object is placed 30 cm from a convex mirror with a focal length of 10 cm?

• 7.5 cm in back

• 15 cm in back

• 30 cm in back

• 7.5 cm in front

If the sun is 150 million km away from the earth, how long does it take sunlight to reach the earth?

• 0.5 s

• 15 s

• 45 s

• 500 s

Two coins are at equal distances from your eye. One is under 40 cm of water, the other under 40 cm of glass. Which coin appears closer?

• the one under the glass

• The one under the water

• The one under the water

The critical angle for total internal reflection at an air-water interface is approximately 48degrees. In which of the following situations will total internal reflection occur?

• light incident in water at 40 degrees

• light incident in water at 55 degrees

• light incident in air at 40 degrees

• light incident in air at 55 degrees

A diverging lens has a focal length of 10 cm. Where is the image located when an object is placed 30 cm from the lens?

• 7.5 cm on the near side

• 15 cm on the near side

• 30 cm on the near side

• 7.5 cm on the far side

A camera employs a .... lens to form..... images.

• converging .... real

• . converging .... virtual

• converging .... virtual

• diverging .... virtual