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प्रश्न
How does the resistance of a wire change when:
its length is tripled?
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उत्तर
Resistance,
`R=l/A`
where l = length of wire
A= area of cross-section of the wire
When the length is tripled, l' = 3l
New resistance,
`R'=l/A `
`R'=(rho(3l))/A=(3l)/A`
`R=3R`
`R=P/A`
Thus, the resistance will become three times the original resistance.
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