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Question
Nichrome and copper wires of same length and same radius are connected in series. Current I is passed through them. Which wire gets heated up more? Justify your answer.
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Solution
Nichrome wire gets heated up more.
We know that nichrome is an alloy whereas copper is a metal and it is known that the resistivity of alloy is greater than the resistivity of metal. This means that resistance of nichrome wire (Rn) is greater than the resistance of copper wire ( Rc)
Also, we know that heat generated (H) across a resistor is given by the expression
H =IRt
or,
H ∝ R
So more the resistance of a wire, more will be heat generated in it.
Hence, we can say nichrome wire gets more heated up as compared to the copper wire.
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