In the figure shown find the total magnification after two successive reflections first on M₁ & then on M₂
Physics · Mixed Chapter
JEE Mains

Question

In the figure shown find the total magnification after two successive reflections first on M₁ & then on M₂

G1 Physics · Accepted Answer

Step 1: From the figure, object-to-M₁ distance is 30 cm, M₁ has signed focal length −20 cm, and the mirror-to-mirror distance is 40 cm. Step 2: Mirror formula for M₁ gives 1/v₁=1/f₁−1/u₁=−1/20+1/30=−1/60, so v₁=−60 cm and |m₁|=|v₁/u₁|=2. Step 3: The first image is 60 cm to the left of M₁, i.e. 20 cm behind M₂. For M₂ (f=+10 cm with its orientation) this is a virtual object: 1/v₂=1/10−1/20=1/20, giving |v₂|=20 cm. Step 4: |m₂|=20/20=1. Total magnification magnitude =|m₁m₂|=2×1=2. Answer: 2.