Single Choice

If the length and area of cross-section of a conductor are doubled, then its resistance will be

Aunchanged
Correct Answer
Bhalved
Cdoubled
Dquadrupled

Solution

We know that the resistance of wire of length $$L$$ and of cross section area $$A$$ is $$R=\dfrac{\rho L}{A}$$ where $$\rho=$$ resistivity of metal of the wire.
When length and cross section are doubled, the resistance becomes $$R'=\dfrac{\rho(2L)}{(2A)}=\dfrac{\rho L}{A}=R$$

SIMILAR QUESTIONS

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