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What is electrical resistivity ? In a se...

What is electrical resistivity ? In a series electrical circuit comprising a resistor made up of a matallic wire, the ammeter reads `5 A`. The reading of the ammeter decreases to half when the length of the wire is doubled. Why ?

Text Solution

Verified by Experts

As `R = (rho l)/(A)`, when `l` is doubled, `R` is also doubled.
Since `I = (V)/(R )`, when `R` is doubled (V remaining unchanged), `I` becomes `I//2`.
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