A copper transmission cable of length must carry a steady current of such that the…

PHYSICS · Single correct · A Level · Physics · Electricity · Electricity

Problem

A copper transmission cable of length 500 m500\,\text{m} must carry a steady current of 50 A50\,\text{A} such that the power lost as heat does not exceed 1000 W1000\,\text{W}. The resistivity of copper is 1.7×10−8 Ω m1.7\times10^{-8}\,\Omega\,\text{m}. Determine the minimum cross-sectional area of the cable. (a) 8.5×10−6 m28.5\times10^{-6}\,\text{m}^2 (b) 2.1×10−5 m22.1\times10^{-5}\,\text{m}^2 (c) 4.3×10−5 m24.3\times10^{-5}\,\text{m}^2 (d) 1.7×10−4 m21.7\times10^{-4}\,\text{m}^2

Related theory

Browse the problem library