Question 182: Ray Optics

Question

A diverging lens with magnitude of focal length 25 cm is placed at a distance of 15cm from a converging
lens of magnitude of focal length 20cm. A beam of parallel light falls on the diverging lens. The final
image formed is:

Accepted Answer

As parallel beam incident on diverging lens so the image will be formed
at the focus of diverging lens.
$$ 	herefore $$ v = Ã¢ÂÂ25 cm
The image formed by diverging lens is used as an object for
converging lens.
So for converging lens
u = Ã¢ÂÂ25 Ã¢ÂÂ 15 = Ã¢ÂÂ40 cm,
f = 20 cm
So Final image formed by converging lens
$${1 \over {20}} = {1 \over V} - {1 \over { - 40}}$$
$$ \Rightarrow $$ V = 40 cm
V is positive so image will be real and will form at right side of converging lens at 40 cm.

Answer

real and at a distance of 6 cm from the convergent lens.

Answer

real and at a distance of 40 cm from convergent lens.

Answer

virtual and at a distance of 40 cm from convergent lens.

Answer

real and at a distance of 40 cm from the divergent lens.

Ray Optics

A diverging lens with magnitude of focal length 25 cm is placed at a distance of 15cm from a converging lens of magnitude of focal length 20cm. A beam of parallel light falls on the diverging lens. The final image formed is:

Choose the correct answer: