Question

the focal length of lens is 80cm.Calucalate Power and nature of lens.

Answer 1

Answer:

concave lens with power -1.25 D.

Explanation:

Here Focal length of lens = 80 cm = 0.8 meter

focal length is calculated as -80 cm or -0.8 meter.

When this value is substituted in the following formula, the power can be calculated:

$P=\frac{1}{f}\\\\P=\frac{1}{-0.8}$

P= -1.25 D (dioptre)

Power is negative so lens will be concave.