IN electic generator is connected to a factory by 2 wires of length 1 km each. The p.d. at generator is 230v and at the factory is 220v.THEcurrent intenisty in the wires is 50A. IF the resestivity of the material of the wire is (1.57 * 10 ^ -6)ohmcm.FIND the resistanceer meter of the wire and its radius.
2006-12-23 20:30:46 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Physics
Potential drop = 230-220 = 10 V
By Ohms Law,
Current(I)*R= V
R=10/50 = 0.2 ohms
Resistance is 0.2 ohms
R=P*l/A
p=(1.57 * 10 ^ -6)ohmcm
l = 2km = 2*100000 cm= 200000cm
A= P*l/R = 1.57*10^-6*2*10^5/0.2 = 1.57 cm^2
A= pi*r^2 = 1.57 (since wire is cylindrical CS area is circular)
r = 0.707 cm
Radius of wire= 0.707 cm
2006-12-23 20:37:00 · answer #1 · answered by Som™ 6 · 2⤊ 0⤋
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2006-12-24 04:36:12 · answer #2 · answered by hari 1 · 0⤊ 3⤋