GK QUESTION#2927
A heating element of a heater is made of a material with high resistivity and high melting point. Which of the following material properties is most crucial for its function as a heating element?
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Answer
D. High resistivity
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Explanation
For a wire of given length and cross-sectional area, R = ρL/A. High resistivity provides a useful resistance in a compact heating element. Joule heating is P = I²R for a given current; this does not mean that raising resistance increases power at a fixed supply voltage.