Question

Make a formula for each of the following statement:

"The reciprocal of the focal length f, is equal to the sum of the reciprocals of the object distance u and image distance v."

• A. $\frac{1}{v}=\frac{1}{f}+\frac{1}{u}$
• B. $\frac{1}{u}=\frac{1}{f}+\frac{1}{v}$
• C. $\frac{1}{f}=\frac{1}{u}+\frac{1}{v}$
• D. $\frac{1}{f}=\frac{1}{v}-\frac{1}{v}$

Answer 1

The correct option is C $\frac{1}{f}=\frac{1}{u}+\frac{1}{v}$

Reciprocal of focal length $f=\frac{1}{f}$

Reciprocal of $u$ and $v=\frac{1}{u}\frac{1}{v}$

So according to the question, $\frac{1}{f}=\frac{1}{u}+\frac{1}{v}$