Question

In a pinhole camera, the image of height 6 cm is formed at a distance of 10 cm. If the object is situated at a distance of 5 cm, the height of the object is:

• A. 3 cm
• B. 6 cm
• C. 1.5 cm
• D. None of these

Answer 1

The correct option is A 3 cm

Magnification can be related to object distance $u$ and image distance $v$.
Magnification, $m=\frac{v}{u}=\frac{10}{5}=2$
Or, $\frac{Heightofimage}{Heightofobject}=2$
Hence, height of object $=\frac{6}{2}=3cm$