1.

The power of lens is -2.5 D. identify the lens and find ‘f’.

Answer»

Here, P = -2.5 D 

f (in metres) = \(\frac{1}{P}\)\(\frac{1}{−2.5}\) = 0.4 m = -40 cm

Negative sign represents concave lens.

Given ,

            Power of lens =  -2.5 D

We know that ,

 D = 1 / f       

 Therefore , f = 1 / D

 = 1 / -2.5   =   - 0.4 m    =     - 40 cm

 The mirror is a concave lens as the focal length is negative .


Discussion

No Comment Found

Related InterviewSolutions