Resistance R of a wire depends on its length L, area A, and resistivity ρ as:
AR = ρ L A
BR = ρ L / A
CR = ρ A / L
DR = ρ / (L A)
Answer & Solution
Correct answer: B. R = ρ L / A
1. R = ρ L / A.
2. Longer wire → more R. Thicker wire (larger A) → less R.
3. ρ is an intrinsic material property; units Ω m.
_Source: NCERT Class 12 Physics Ch 3 §3.5 Resistance of Conductors_
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