Q. At what temperature will the resistance of a copper wire become three times its value at $0℃$ (Temperature coefficient of resistance for copper = $4 \times 10^{- 3}per\ ℃$)
A) $400℃$
B) $450℃$
C) $500℃$
D) $550℃$
Explanation
(c) By using $R_{t} = R_{0}(1 + \alpha t)$
$3 \times R_{0} = R_{0}\left( 1 + 4 \times 10^{- 3}t \right) \Rightarrow t = 500℃$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.