Question

The I-V graph for a conductor at two different temperatures 100°C and 400°C is as shown in the figure. The temperature coefficient of resistance of the conductor is about (in per degree Celsius)

• A. \( 3 \times 10^{-7} \)
• B. \( 6 \times 10^{-7} \)
• C. \( 9 \times 10^{-7} \)
• D. \( 12 \times 10^{-7} \)

Answer 1

The Correct Option is A

The temperature coefficient of resistance \( \alpha \) quantifies how much the resistance of a material changes with temperature.
The formula for calculating \( \alpha \) is:\( \alpha = \frac{R_2 - R_1}{R_1 (T_2 - T_1)} \) 
where \( R_1 \) and \( R_2 \) are the resistances at temperatures 
\( T_1 = 100^\circ \text{C} \) and \( T_2 = 400^\circ \text{C} \), respectively. 
Using the graph, you can estimate the resistance at these temperatures, and after performing the calculation, you find:
\( \alpha = 3 \times 10^{-7} \, \text{°C}^{-1} \)