find the focal length of lens of power -2.0 D . what type of lens is this?
Answers
Answered by
8
Answer:
The power of the lens given is -2D.
It has negative sign, which means that it is a concave lens.
Now, the formula for the power is P = 1/f.
Let’s put the given value. -2 = 1/f
On simplifying we get, f = -1/2 m
By converting the result into centimetres, we get, f = -1/2 X 100
Therefore, focal length =-50cm.
Similar questions