Question

plz answer this question
(A) Device X is a concave mirror and device Y is a convex lens, whose
focal lengths are 20 cm and 25 cm respectively."
(B) Device X is a convex lens and device Y is a concave mirror, whose focal
lengths are 10 cm and 25 cm respectively.
(C) Device X is a concave lens and device Y is a convex mirror, whose focal
lengths are 20 cm and 25 cm respectively.
(D) Device X is a convex lens and device Y is a concave mirror, whose focal
lengths are 20 cm and 25 cm respectively.
(CBSE 2017)​

Answer 1

Explanation:

the option a is appropriate

Answer 2

Answer:

(D) Device X is a convex lens and device Y is a concace mirror, whose focal lengths are 20cm and 25cm respectively.

Explanation:

The Device X converges the light beams through it, whose focal lenght is 20cm. and opposite is the case for Y.

I hope it helps ^_^