Question

doctor advise a person to use -1.50 lens. what is the focal lenth of lens and what type of lens is that​

Answer 1

Answer:

The focal length of the concave lens is 67 cm.

Explanation:

Power = $\frac{1}{f}$

Therefore,

-1.50 = $\frac{1}{f}$

f = $\frac{1}{1.5}$

f = -0.66666...

f ≈ -0.67 m

f ≈ -67 cm

The lens is a concave (diverging lens) because its focal length has a negative sign. The focal length of a concave lens is always taken as negative.