Question 120: Ray Optics

Question

An object is placed at the focus of concave lens having focal length f. What is the magnification and distance of the image from the optical centre of the lens?

Accepted Answer

U = $$-$$f
$${1 \over V} - {1 \over U} = {1 \over { - f}} \Rightarrow {1 \over V} =  - {2 \over f}$$
$$V = {{ - f} \over 2}$$
$$m = {V \over U} = {1 \over 2}$$
distance = $${f \over 2}$$
Option (c)

Answer

1, $$\infty$$

Answer

Very high, $$\infty$$

Answer

$${1 \over 2}$$, $${f \over 2}$$

Answer

$${1 \over 4}$$, $${f \over 4}$$

Ray Optics

An object is placed at the focus of concave lens having focal length f. What is the magnification and distance of the image from the optical centre of the lens?

Choose the correct answer: