Question

The current through an electrical conductor is 1A when the temperature of the conductor 0°C and 0.7 A when the temperature is 100°C. The current when the temperature of the conductor is 1200°C is ___________

(a) 0.08 A

(b) 0.16 A

(c) 0.32 A

(d) 0.64 A

This question was addressed to me during an interview for a job.

This question is from Problems Involving Dot Conventions in division Resonance & Magnetically Coupled Circuit of Network Theory

Answer 1

Right choice is (b) 0.16 A

To elaborate: \(\frac{1}{0.7} = \frac{R_O (1+αt)}{R_O}\)

= 1 + α100

∴α = 0.0043 per °C

Current at 1200 °C is given by, \(\frac{1}{I} = \frac{R_O (1+α1200)}{R_O}\)

= 1 + α1200

= 1 + 0.0043 × 1200 = 6.16

∴ I = \(\frac{1}{6.16}\) = 0.16 A.