Question

A doctor has prescribed a corrective lens o f power +1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging?​

Answer 1

Answer:

0.67 m

Explanation:

Given,

Power, P = + 1.5 D

Focal Length, f = 1/P

= 1/1.5 m

= 0.67 m

As the power of the lens is positive, lens is convex lens i.e. the prescribed lens is converging.

Thank you!

Mark me as brainliest if it is helpful.

Answer 2

Given :

Power of the lens = +1.5 D.

To Find :

The focal length of the lens and the prescribed lens diverging or converging.

Solution :

The power of this lens is positive so it is a convex lens or a converging lens.

We know that,

» The power is the reciprocal of the focal length that is

$\boxed{ \bf P = \dfrac{1}{f} }$

where,

• P denotes power of the lens
• f denotes the focal length

By, substituting the given values in the formula,

$\dashrightarrow\sf P = \dfrac{1}{f}$

$\dashrightarrow\sf 1.5 = \dfrac{1}{f}$

$\dashrightarrow\sf f = \dfrac{1}{1.5} m$

$\dashrightarrow\sf f = \dfrac{1}{1.5} \times 100 \: cm$

$\dashrightarrow\sf f = + 66.7 \: cm$

Thus, the focal length of the lens is +66.7 cm.