A heating element has a resistance of 100 Ω at room temperature. When it is connected to a supply of 220 V , a steady current of 2 A passes in it and temperature is 500 o C more than the room temperat

Question

A heating element has a resistance of 100 Ω at room temperature. When it is connected to a supply of 220 V , a steady current of 2 A passes in it and temperature is 500 o C more than the room temperature. The temperature coefficient of resistance of the heating element is

TestHub · Accepted Answer

Resistance of heating element after temperature increases by $500^{o} C = \frac{220}{2} = 110 Ω$ (from Ohm's law). The new resistance is related to the temperature coefficient of the heating element as $110 = 100 (1 + α 500)$

$α = \frac{10}{100 \times 500}$ $\Rightarrow α = 2 \times 10^{- 4} ° C^{- 1}$

Physics - Current Electricity Question with Solution | TestHub

Options:

Doubts & Discussion