Question

If two lenses are placed in contact, the combination has power equal to

• A. Algebraic sum of power of two lenses
• B. Division of power of two lenses
• C. Multiplication of power of two lenses
• D. Subtraction of power of two lenses

Answer 1

Answer: (A)

Algebraic sum of power of two lenses

If the lenses of focal lengths f 1 and f 2 are thin, the combined focal length ,If the separation distance is equal to the sum of the focal lengths (d = f 1+f 2), the net convergence or divergence of the beam, i.e. has an infinite effective focal length. The simplest case is where lenses are placed in contact and if the lenses of focal.