Question

What is the formula for magnification obtained with a lens?

a) Ratio of height of image to height of object

b) Double the focal length.

c) Inverse of the radius of curvature.

d) Inverse of the object distance.​

Answer 1

Solution:

The magnification of the lens is given by the formula,

$\implies\boxed{\sf{m = \dfrac{v}{u}=\dfrac{h_i}{h_o}}}$

here,

• m = magnification
• v = image distance
• u = object distance
• hi = height of image
• ho = height of object

The answer is both a and d.

Extra Information:

• The focal length of the concave lens is negative.
• The focal length of the convex lens is positive.
• Distances are always measured from the optical center of the lens.