The tow ends of a long gold mef are connected to the Tcrmina

The tow ends of a long gold mef are connected to the Tcrminals of a battery of EMI 12 v crimim A gose circuit gold wet has a length of 9.50m, Diameter of 0.760mm, are sistivity op 2.44 times 10 ^-8 ohm At 20\'c 1/3 the co

Solution

a) dependence of resistivity on temperature.

rho = rho0 (1 + alpha*deltaT)

rho = 2.44 x 10^-8 (1 + ( 3.4 x 10^-3) (100-20) )

rho = 3.104 x 10^-8 ohm m

resistance, R = rho * L /A

R = (3.104 x 10^-8 x 950 ) / ( pi x (0.780 x 10^-3 / 2)^2 )

R = 61.71 ohm

b) I = V / R = 12 / 61.71 =0.194 A

field = V/L = 12 / 950 = 0.016 V/m

c) now Req = 61.71 + 10 = 71.71 ohm

I = 12 / 71.71 = 0.167 A

P = i^2 R = 0.167^2 x 10 = 0.28 W