While taking photographs in Death Valley on a day when the t

While taking photographs in Death Valley on a day when the temperature is 56.0°C, Bill Hiker finds that a certain voltage applied to a iron wire produces a current of 1.000 A. Bill then travels to Antarctica and applies the same voltage to the same wire. What current does he register there if the temperature is -88.0°C? Assume that no change occurs in the wire\'s shape and size.
1 A

Solution

The temperature coefficient of copper = 0.0039 deg c ^-1 for T_o = 20 deg

R_h = 1 + alpha (T_h - T_o) = 1 + 0.0039(56 - 20)

= 1.14

R_C = 1 + alpha (T_C - T_o) = 1 + 0.0039(-88 - 20)

= 0.5788

I_C = I * R_h / R_C

= (1.00) * (1.14 / 0.5788)

= 1.97 A