Question

Two lenses of power +1.5 d and -1.0d are placed in contact with each other.

Answer 1

Answer:

Two lenses of power +3.5 D and -1.5 D are placed in contact . ... Two lenses of power = 1.5 D and 3.5 D. so, P1 + P2 = 3.5 + (-1.5) = 3.5 - 1.5 = 2 D...................... ....

Answer 2

the power of combined lenses is 0.5

Explanation:

power of lenses

lens 1 =+1.5 d

lense 2 =_1.0 d

by adding both of these we get +1.5_1.0=0.5