Given, focal length of lens (f) = 15 cm object is placed at a distance (u) = – 20 cm By lens formula,
1
f
=
1
v
−
1
u
1
v
=
1
f
+
1
u
=
1
15
−
1
20
1
v
=
4−3
60
v=60cm The image I gets formed at 60 cm to the right of the lens and it will be inverted. The rays from the image (I) formed further falls on the convex mirror forms another image. This image should formed in such a way that it coincide with object at the same point due to reflection takes place by convex mirror. Distance between lens and mirror will be d = image distance (v) – radius of curvature of convexmirror 5=60−2f 2f=60−5 f=