Question

A wire is stretched to double such that its length increases by 20%, calculate % change in its resistance

Answer 1

hey there,

we know the resistance of a wire can be represented by the following equation:-

R = p l/ A = 20

ie :- R' = p l/A'

= p 2 l/A/2

= 4p l/A

= 4R

= 80ohm.

so, when the conductor made thinner, it's area of cross section will decrease , since resistance is inversely proportional to the area of the conductor. therefore, it's resistance will increase.

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BEST OF LUCK :-)

#akashmandal.