Question

Where is the image located when an object is 60 cm from a convex mirror with a focal length of20 cm?
15 cm behind
30 cm behind
60 cm behind
15 cm in front

Answer 1

Answer on Question #46981-Physics-Optics

Where is the image located when an object is 60 cm from a convex mirror with a focal length of 20 cm?

- 15 cm behind

- 30 cm behind

- 60 cm behind

- 15 cm in front

Solution

Here $u = -ve, f = +ve$.

$$\frac{1}{u} + \frac{1}{v} = \frac{1}{f}.$$ $$\frac{1}{-60} + \frac{1}{v} = \frac{1}{20} \rightarrow v = 15 \text{ cm}.$$

The $+ve$ sign indicates that image is virtual and behind the mirror.

Answer is 15 cm behind.

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