Answer to Question #162172 in Electric Circuits for Kyla Nickles

Question

A tungsten filament lamp has a resistance of 11.8 ohms at 20 degrees Celsius. Determine its resistance at 2500 degrees Celsius

Answer 1

Calculate the value of the difference in the temperature.

$ΔT = T_2 -T_1 \\ = 2500 -20 \\ = 2480 \;ºC$

Consider the expression for the new value of the temperature due to increase in the temperature.

$R_2 =R_1(1 + αΔT) \\ = 11.8 (1 + 0.0045 \times 2480) \\ = 11.8 (1 +11.16) \\ = 11.8 \times 12.16 \\ = 143.5 \;Ω$

Answer: 143.5 Ω