Question

The temperature coefficient of resistance of a wire is 0.00125 per degree celsius . At 300 K temperature its resistance is 1 ohm. The resistance of the wire will be 2 ohm at:


(a) 1154 K

(b) 1100 K

(c) 1400 K

(d) 1127 K

Answer 1

let R1 be resistance in First case and temperature be t1.
let at t2 temperature resistance will be r2.
.and temperature coefficient of resistance be alpha.
now Given.
R1= 1 ohm
R2 = 2ohm
t1= 300K = 27°C .
t2= ?.
see picture!!for solution!!....

since !!.
option d is correct...
hope it helped you!!....

Answer 2

Answer:

B) 1100K

Explanation:

Initial temperature of the wire = 27°C (Given)

Initial resistance of the wire = 1 (Given)

Temperature coefficient of the wire = (1.25 10-3)c-1 (Given)

Resistance of wire is a linear function of temperature.

Therefore,

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

Thus, the resistance of the wire will be 2 ohm at 1100 K.