Question

The temperature coefficient of resistance of a wire is 0.00125 per°C- At 300 K, its resistance is 1 ohm. This resistance of the wire will be 2 ohm at [1980]
a)1154 K   b) 1100 K    c) 1400 K  
 d) 1127 K​

Answer 1

yoo it is simple here is your required solution have a look

➡️ Initial temperature = 300 K = 27°C

Resistance of wire is a linear function of temperature.

➡️ α = ΔR / (RΔθ)

➡️ Δθ = ΔR / (Rα)

(T - 27) = (2 Ω - 1 Ω) / (1 Ω × 0.00125 /°C)

➡️ T - 27 °C = 800 °C

➡️ T = 27 °C + 800°C

➡️ T = 827 °C

➡️ T = (827 + 273) K

➡️ T = 1100 K

Temperature of wire will be 1100 K.