ExamBro
ExamBro
COMEDK · Physics · 19. Current Electricity

The resistance of a wire at room temperature \(20^\circ\text{C}\) is found to be \(10\Omega\). If resistance of the wire increases by \(10\%\), then the temperature of the wire will be (The temperature coefficient of the material of the wire at \(0^\circ\text{C}\) is \(0.002/^\circ\text{C}\))

  1. A \(52^0 \mathrm{C}\)
  2. B \(72^0 \mathrm{C}\)
  3. C \(22^0 \mathrm{C}\)
  4. D \(62^0 \mathrm{C}\)
Verified Solution

Answer & Solution

Correct Answer

(B) \(72^0 \mathrm{C}\)

Step-by-step Solution

Detailed explanation

\(R_1 = 10\ \Omega\) at \(T_1 = 20°C\), \(R_2 = 11\ \Omega\) (10% increase), \(\alpha_0 = 0.002/°C\) Using \(R_T = R_0(1 + \alpha_0 T)\): \(\dfrac{R_2}{R_1} = \dfrac{1 + \alpha_0 T_2}{1 + \alpha_0 T_1}\)…