A convex lens of focal length 80 cm and a concave lens of focal length 50 cm are combined together. The resulting power is:
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Question

A convex lens of focal length 80 cm and a concave lens of focal length 50 cm are combined together. The resulting power is:

G1 Physics · Accepted Answer

Step 1: Convert focal lengths: f₁ = +0.80 m, f₂ = −0.50 m. Step 2: Powers: P₁ = +1.25 D, P₂ = −2.00 D. Step 3: P_total = P₁ + P₂ = −0.75 D. Final answer: (D) −0.75 D.