The temperature coefficient of resistance of platinum is α=3.92×10−1 K−1 at 20oC. Find the temperature at which the increase in the resistance of platinum wire is 10 of its value at 20oC
Given,
Resistance at 20oCis1Ω
Increase in temperature, ΔR=10Ω
ΔR=αR20ΔT=
⇒10=3.92×10−1×1×(T−20)
⇒T=45.5oC
Hence, at 45.5oC resistance increased by 10Ω