An object of height 2.5cm is places 20cm from a convex mirror of focal length 10cm. Calculate the height of its image.
-
2.5 cm
- 3.0cm
- 5.0cm
- 25.0cm
The correct answer is: A
Explanation
\(\frac{1}{v} = \frac{1}{f} - \frac{1}{u}\)
= \(\frac{1}{10} - \frac{1}{2} = \frac{1}{20}\)
v = 20
but h\(_i\) = \(\frac{v \times h_o}{u}\)
= \(\frac{20 \times 2.5 }{20}\)
= 2.5cm