An object is placed 20cm from a concave mirror of focal length 15cm. Calculate the linear magnification of the image formed
- 0.5
- 1.5
- 2.0
-
3.0
The correct answer is: D
Explanation
\(\frac{1}{U} + \frac{1}{V} = \frac{1}{F}\)
\(\frac{1}{V} = \frac{1}{F} - \frac{1}{U}\)
\(\frac{1}{V} = \frac{1}{15} - \frac{1}{20}\)
\(\frac{1}{V} = \frac{\text{4 - 3}}{60}\)
\(\frac{1}{V} = \frac{1}{60}\)
V = 60cm
M = \(\frac{V}{U} = \frac{60}{20}\)
M = 3.0cm