Physics
If a wire of resistance 2Ω gets stretched to thrice its original length :
(a) Calculate the new resistance of the wire.
(b) What happens to the specific resistance of the wire?
Current Electricity
ICSE 2022
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Answer
(a) Given, R = 2Ω
⇒ ρ = 2Ω
Let new resistance be R'.
New length =
New Area =
∴ R' = ρ
= ρ
= 9R = 9 × 2 = 18Ω
Hence, new resistance = 18Ω
(b) Specific resistance of the wire remains unchanged since it does not depend on the dimensions of the wire. It is the characteristic property of the substance.
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