Check sibling questions

Find the focal length of a lens of power – 2.0 D. What type of lens is this?

 

Answer

Given

Power of lens = –2.0 D

 

We know that,

Power of the lens = 1/Focal length

–2 = 1/Focal Length

Focal length = 1/(–2)

Focal length = –0.5 m


Since the focal length is negative, the lens is a concave lens.

 

sign-convention-for-lens---teachoo2.jpg

Learn in your speed, with individual attention - Teachoo Maths 1-on-1 Class

Ask a doubt
Maninder Singh's photo - Co-founder, Teachoo

Made by

Maninder Singh

CA Maninder Singh is a Chartered Accountant for the past 13 years and a teacher from the past 17 years. He teaches Science, Economics, Accounting and English at Teachoo