While taking photographs in Death Valley on a day when the temperature is 57.0°C

Question

While taking photographs in Death Valley on a day when the temperature is 57.0°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

__A

Have had 2 other wrong answers on this question. Please try and get correct. Last question available to ask for month...

Thank you!

Explanation / Answer

Let denote the temperature coefficient
alpha = 3.4 x10^-3 K^-1.

1/alpha = 294K = 21*C

T0 = 21C = 294 K.
T1 = 330 K
T2 = 185 K

R1 = (1 + alpha(T1-T0))*R0
R2 = (1 + alpha(T2-T0))*R0, or

R2/R1 = (1 + alpha(T2-T0))/(1 + alpha(T1-T0)) =
0.6294/1.1224 = 0.5607

Current:
I2 = (1 + alpha(T1-T0))/(1 + alpha(T2-T0)) * I1

I2 = 1.7832 A

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.