Question

An object is placed at the centre of curvature of a concave mirror of focal length 16 cm. If the object is shifted by 8 cm towards the focus, the nature of the image would be _________.

• A. real and magnified
• B. virtual and magnified
• C. real and reduced
• D. virtual and reduced

Answer 1

The correct option is A real and magnified

Initial distance of object from the mirror $=2|f|=2\times 16=32cm$
New object distance $u=32-8=24cm$
Using $\frac{1}{v}+\frac{1}{u}=\frac{1}{f}$
Or $\frac{1}{v}+\frac{1}{-24}=\frac{1}{-16}$
$⟹v=-48cm$ (where negative sign implies that image is real)
Magnification $m=\frac{-v}{u}=\frac{-(-48)}{-24}=-2$
So magnified inverted image is formed.