Question

# A point object O is placed at a distance of 20 cm from a convex lens of focal length 10 cm as shown in Fig. At what distance x from the lens should a concave mirror of focal length 60 cm, be placed so that final image coincides with the object?

A
10cm
No worries! Weâ€˜ve got your back. Try BYJUâ€˜S free classes today!
B
40cm
No worries! Weâ€˜ve got your back. Try BYJUâ€˜S free classes today!
C
20cm
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
Final image can never coincide with the object in the given conditions
No worries! Weâ€˜ve got your back. Try BYJUâ€˜S free classes today!
Open in App
Solution

## The correct option is B 20cmObject is placed at a distance of 2f from the lens (f= focal length of lens), i.e., the image formed by the lens will be at a distance of 2f or 20 cm from the lens. So, if the concave mirror is placed in this position, the first image will be formed at its pole and it will reflect all the rays symmetrically to other side and the final image will coincide with the object.

Suggest Corrections
0
Related Videos
Lens Formula, Magnification and Power of Lens
PHYSICS
Watch in App
Explore more