Question

2 thin lenses of power +3D and -2.5D are placed in contact. calculate power and focal length of the combination​

Answer 1

Answer:

the power will be 3D+(-2.5D)=0.5

the focal length will be 1/0.5=2

Answer 2

Answer:

the power will be 0.5

the focal length will be=2

Explanation:

AS,

     P(total) =P1 + P2 + P(n)

So,

      P(total) =3D+(-2.5D)= 0.5D

NOW FOCAL LENGTH,

      F =  1/0.5 =2

PLEASE AS BRAINLIEST