Nickel wire at 0 ° C has a resistance of 40 ohms. At what temperature will its resistance become 42 ohms?

Problem data: t0 (initial temperature of nickel wire) = 0 ºС; R0 (resistance of nickel wire at temperature t0) = 40 Ohm; R (required wire resistance) = 42 ohms.

Reference values: α (thermal resistance coefficient of nickeline) = 0.0001 K-1.

The temperature at which the resistance of the nickelin wire becomes equal to 42 ohms can be expressed from the formula: R0 = R / (1 + α * t), whence α * t = R / R0 – 1 and t = (R / R0 – 1) / α …

Calculation: t = (42/40 – 1) / 0.0001 = 500 ºС.