Unit: Geometric Optics Year: 1997 Question#: 86
Question: In the diagram below, a source produces a light ray that is reflected from a plane mirror.
To an observer at point O , the light appears to originate from point
(1 ) A.
(2 ) B.
(3 ) C.
(4 ) D.
What is this question really asking?
Explanation by: Josh S
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Answer 1
A
INCORRECT
This point is in front of the mirror. There is obviously not an image floating in space due to the fact that it is a plane mirror. This could happen with some sort of curved mirror such as a converging mirror.
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Answer 2
B
CORRECT
The image would be shown equidistant from the original source. It would also be along the proper angle of reflection. Look at ray D. This is where the light from the source is reflected. Looking at the mirror you would see the image along ray D, however you would need to look past the mirror, to point B. return to top
Answer 3
C
INCORRECT
An object appears a distance away from the mirror that is equal to the actual distance from the mirror, therefore it is impossible for the object to appear directly on the mirror. return to top
Answer 4
D
INCORRECT
This point is in front of the mirror. There is obviously not an image floating in space due to the fact that it is a plane mirror. This could happen with some sort of curved mirror such as a converging mirror.
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What's this question really asking?
This question is really asking exactly what it asks for. If you were an observer at point O, the light would appear to originate from what point? return to top
