Question

A convex mirror and a concave mirror of radius $10cm$ each are placed $15cm$ apart facing each other. An object is placed midway between them. If the reflection first takes place in the concave mirror and then in convex mirror, the position of the final image is

• A. On the pole of the convex mirror
• B. On the pole of the concave mirror
• C. At a distance of $10cm$ from the convex mirror
• D. At a distance of $5cm$ from the convex mirror

Answer 1

Answer: (A)

On the pole of the convex mirror

for concave mirror $u=-7.5$ ; $f=-5$

$\frac{1}{v}+\frac{1}{u}=\frac{1}{f}$

$\frac{1}{v}-\frac{2}{15}=\frac{-1}{5}$

$v=-15$

i.e, image is formed at pole of convex mirror for convex mirror , $u=0$ ;$f=+5$

$\frac{1}{v}+\frac{1}{u}=\frac{1}{f}$

$\frac{1}{v}+\frac{1}{0}=\frac{1}{5}$

$v=0$

so final image is formed at pole of convex mirror , hence option $A$ is correct