PH 202

Quiz # 07 (10 pts)

Name

Solution

 

A man is preening 1.70 m in front of a plane mirror.  Which of the following best describes the image formed by the plane mirror?

 

A.

The image of the man is formed 1.70 m in front of the mirror and is a real image.

 

 

B.

The image of the man is formed 1.70 m in front of the mirror and is a virtual image.

 

 

C.

The image of the man is formed 1.70 m behind the mirror and is a real image.

 

 

D.

The image of the man is formed 1.70 m behind the mirror and is a virtual image.

 

The image forms behind the mirror since the law of reflection holds.  The image is virtual since the light rays do not really come to a focus behind the mirror but only appear to form there.  If you were behind the mirror, you would not see the image.  So it is virtual.

 

So Correct Answer is D !

 

Light rays travel from an object very far away from a concave mirror, which has a radius of curvature .  After the rays strike the mirror, an image is formed which can best be described as:

 

A.

The image is formed at  in front of the mirror and is upright.

 

 

B.

The image is formed at  in front of the mirror and is inverted.

 

 

C.

The image is formed at  in front of the mirror and is inverted.

 

 

D.

The image is formed at  in front of the mirror and is upright.

 

The image being very far away means its object distance is infinity .  Thus the image will form at the focal length of the mirror which is one half the radius of curvature or

 

 

It is a real image so it will be inverted.

 

There was a typo obviously 23 is not 28.  So All answers were considered correct.  The intent was answer C would be correct in that the image would be in front of mirror, real and inverted.  Again, this question is scored correct for all who took the quiz.

 

A  tall object is located  to the left of a concave spherical mirror whose focal length is .  Which of the following best describes the image formed by the mirror?

 

A.

 to the left of the mirror and inverted.

 

 

B.

 to the left of the mirror and upright.

 

 

C.

 to the right of the mirror and upright.

 

 

D.

 to the right of the mirror and inverted.

 

 

 

 

This is a real image so it will be to the left of the mirror and inverted

 

So Correct Answer is A !

 

An object  tall sits on the left side of a convex spherical mirror whose radius of curvature is .  The image is formed to the right of the mirror.  How far away was the object?

 

A.

B.

C.

 

D.

 

 

 

 

 

So the Correct Answer is B !

 

An object is  tall and is located  to the left of a concave spherical mirror with a focal length of .  The image is found to be  to the left of the spherical mirror.  How tall is the image and is it upright or inverted?

 

A.

C.

 

 

 

 

B.

D.

 

Solving for the image height

 

 

- sign indicates inverted!

 

So Correct answer is A !

 

 

 

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This page last updated on October 23, 2020