Question

The potential difference between the ends of a wire at all temperatures is constant and is \(240\,\text{V}\). When the temperature of the wire is increased from \(0^\circ\text{C}\) to \(1000^\circ\text{C}\), its resistance increases by \(25\,\Omega\). If the temperature coefficient of resistance of the material of the wire is \(1.25\times10^{-4}\,^\circ\text{C}^{-1}\), then the current through the wire at \(0^\circ\text{C}\) is

• A. \(0.6\,\text{A}\)
• B. \(1.2\,\text{A}\)
• C. \(1.8\,\text{A}\)
• D. \(2.4\,\text{A}\)

Hint:

For metallic conductors, \[ \boxed{ R_t=R_0(1+\alpha t). } \] If the potential difference is constant, \[ \boxed{ I=\frac{V}{R}. } \] As temperature increases, the resistance increases and the current decreases.

Answer 1

The Correct Option is B