Question

An object is placed at a distance of $5cm$ from a convex lens of focal length $10cm$. The image formed is:

• A. Real and inverted
• B. Real and enlarged
• C. Virtual and diminished
• D. Virtual and enlarged

Answer 1

The correct option is D Virtual and enlarged

Given:- $u=-5cm$ and $f=10cm$

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

$⟹\frac{u}{v}-1=\frac{u}{f}$

$⟹\frac{1}{m}=1+\frac{1}{f}$ , $m$=magnification

$⟹m=\frac{f}{f+u}$

$⟹m=\frac{10}{10-5}=2$

Since, magnification is positive and is greater than 1.

Hence, image formed is virtual, erect and enlarged.

The question can also be solved without going in mathematical calculations just by locating that the object is placed between optical center and focus of the lens, hence enlarged and virtual image will be formed.

Answer-(D)