A nichrome wire of length 1.5 m and diameter 0.40 mm is to be used as a heating element
PHYSICS · Multi-part · CBSE · Physics · Current Electricity · Current Electricity
Problem
A nichrome wire of length 1.5 m and diameter 0.40 mm is to be used as a heating element. The resistivity of nichrome at room temperature is 1.10 × 10⁻⁶ Ω·m.
(i) Calculate the resistance of the wire at room temperature.
(ii) The wire is connected across a 12 V battery of negligible internal resistance. Determine the current through the coil and the power it dissipates.
(iii) If the same wire were replaced by a manganin wire of identical dimensions whose resistivity is 4.2 × 10⁻⁷ Ω·m, find the percentage change in the power dissipated for the same applied voltage.