Question

A combination of two lenses with power 1D and 2D is there. What is the total power?

Answer 1

Step 1: Given data:

Power of Lenses in contact

The power of n number of lenses in contact is equal to the algebraic sum of the power of n individual lenses.

Given, Powers,

$$\begin{gathered} P_1=1D \\ {P}_2=2D \end{gathered}$$

Step 2: Calculation:

So,

$$\begin{gathered} P=P_1+P_2 \\ P=1+2 \\ P=3D \end{gathered}$$

Here, P is total power.

Hence, the total power of a combination of two lenses with power 1D and 2D is 3D.