Question

X=+10 cm, Y=-15 cm. the focal length of two lences X and Y are given. which of the concave lens and convex lens.​

Answer 1

Answer:

X = 10

therefore the lens is convex because the focal length of it is always positive

y= -15

therefore the lens is concave because the focal length of this always negative

Answer 2

Answer:

concave lens-Y because the focal length is negative in case of concave lens and convex lens -X is focal length is positive