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PHY 104 PHY 104 Past Questions Objective Question
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Question

An object is placed 100 cm in front of a convex mirror of radius 50 cm. The image formed is
Options
A virtual and 20 cm in front of the mirror
B virtual and 20 cm behind the mirror
Correct Answer
C real and 20 cm behind the mirror
D virtual and 40 cm behind the mirror
Correct Answer

Option B is the correct answer.

Detailed Explanation

For a convex mirror, the focal length (f) is positive and is equal to R/2 = 25 cm. The mirror equation is 1/f = 1/u + 1/v. With u = -100 cm (object distance). 1/25 = 1/(-100) + 1/v => 1/v = 1/25 + 1/100 = 4/100 + 1/100 = 5/100 = 1/20. So v = 20 cm. Since v is positive, the image is virtual and formed behind the mirror.

Hint

Use the mirror equation: 1/f = 1/u + 1/v. For a convex mirror, f is positive. The image distance (v) for a virtual image is positive.

Question Info

Course: PHY 104
Topic: PHY 104 Past Questions
Type: Objective
Difficulty: Not specified
Question 743 of 947
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