Question

5/20
A spherical mirror and a thin spherical
lens have each focal length of -12 cm
The mirror and the lens are likely to be
the mirror is concave and
the lens is convex
the mirror is convex and the
lens is concave
C
both concave
D
both convex​

Answer 1

concave mirror and convex lens

Answer 2

Hey there!

Amongst convex and concave mirrors according to sign convention we can say that a concave mirror has a negative focal length

similarly if check the sign convention for a concave lens the focal length of a concave lens is also negative

so your answer is both concave

Hope it helps!