Solve the following examples.

Three lenses having power 2, 2.5 and 1.7 D are kept touching in a row. What is the total power of the lens combination?

Answer:

As per the given question three lenses having power 2, 2.5 and 1.7 D are kept touching in a row.

So resultant power will be

P=P1+P2+P3

P= 2+2.5+1.7

P= 6.2D

The resultant combination 6.2D is of convex lens and it will produce a converging effect.

Lens Formula, Magnification and Sign Convention