Science, asked by mansi161203, 1 year ago

how much resistance change if the diameter is doubled?​

Answers

Answered by sahana61
2
Let the length of the wire is L, resistivity is ρ and diameter is d. The resistance of the wire is R=4ρL ∕ (πd²). Now if the diameter is doubled then the new resistance is R’=4ρL∕(π(2d)²) =4ρL∕(4πd²) =0.25R. Hence we see that the resistance of the wire becomes 25% of original resistance. This result is showing that the resistance decreases as we increase the cross-section area keeping the length constant.


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Answered by Anonymous
1
we know that

R=(density *length)/area

R is inversely proportional to area

let initial diameter be x

new diameter=2x

now according to question

R is inversely proportional to square of radius since π is constant

final resistance=1/4x^2 -1/8x^2

=1/8x^2
in percentage 2x^2*100/8x^2
25%
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