Question

Concave lens of focal length 20 cm and double convex lens of focal length 30 cm are placed 15 cm apart on their common axis

Answer 1

Answer:

A concave lens of focal length \( 20 \mathrm{cm} \) and double convex lens of focal length \( 30 \mathrm{cm} \) are placed 15 \( \mathrm{cm} \) apart on their common axis. If an object is placed at distance \( x \) in front of concave lens then value of \( x \) so that image is formed at infinity is.