Question:
A concave mirror for face viewing has focal length of 0.4 m. The distance at which you hold the mirror from your face in order to see your image upright with a magnification of 5 is :
A concave mirror for face viewing has focal length of 0.4 m. The distance at which you hold the mirror from your face in order to see your image upright with a magnification of 5 is :
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Use \(m = \frac{f}{f - u}\) with the sign convention (concave mirror: \(f = -0.4\) m, object distance \(u = -d\)), with \(m = +5\) for an upright image.
Updated On: Nov 5, 2026
- \(0.24\) m
- \(0.32\) m
- \(1.60\) m
- \(0.16\) m
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The Correct Option is B
Solution and Explanation
Take \(f = -0.4\) m and \(u = -d\). \(m = \frac{f}{f - u} = \frac{-0.4}{-0.4 + d} = 5\).
\(-0.4 = -2 + 5d \Rightarrow 5d = 1.6 \Rightarrow d = 0.32\) m.
Answer: (2) \(0.32\) m
\(-0.4 = -2 + 5d \Rightarrow 5d = 1.6 \Rightarrow d = 0.32\) m.
Answer: (2) \(0.32\) m
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