First slide

Ray optics

Question

Al object is placed at a distance of f/2 from a convex lens. The image will be

Moderate

A

At one of the foci, virtual and double its size
B

At 3 f/2, real and inverted
C

At 2 f, virtual and erect
D

None of these

Solution

$\begin{array}{l} \frac{1}{f} = \frac{1}{v} + \frac{1}{u} (Given u = \frac{- f}{2}) \\ \Rightarrow \frac{1}{f} = \frac{1}{v} + (\frac{1}{f / 2}) \Rightarrow \frac{1}{v} = \frac{1}{f} - \frac{1}{f} \\ \Rightarrow \frac{1}{v} = \frac{- 1}{f} and m = \frac{v}{u} = \frac{f}{f / 2} = 2 \end{array}$
So virtual at the focus and of double size.

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App