Question

¡¡ Need well explained Answer ¡¡

A convex lens produces an inverted image magnifies 3 times of an object placed at a distance of 15 cm from it. calculate the focal length of lens.​

Answer 1

$~~~~~~~~$${\bf{Given :}}$

• A convex lens produces an inverted image magnifies 3 times of an object placed at a distance of 15 cm from it.

$~~~~~~~~$${\bf{To Find :}}$

• The focal length of lens.

$~~~~~~~~$${\bf{Solution :}}$

Object Distance, u = -15 cm

Magnification, m = -3 (Image is Inverted)

Applying magnification formula, we get :

${\bf{m = \frac{V}{U} = - 3 }}$

➞ ${\bf{\frac{v}{ - 15} = - 3}}$

➞ ${\bf{v = 45cm:}}$

Applying Lense formula we get,

${\bf{\frac{1}{v} - \frac{1}{u} = \frac{1}{f}}}$

➞ ${\bf{1/45 - 1/-15 = 1/f}}$

➞ ${\bf{1/f = ( 1+3 )/45}}$

➞ ${\bf{1/f = 4/45}}$

➞ ${\bf{or f = 11.2 cm}}$

Hence, focal length of the lens is 11.2 cm.

Answer 2

Answer:

I THINK IT IS HELPFUL TO YOU ...