A cylindrical wire is compressed in length by 10%. The
percentage decrease in the resistance will be?????

Answer Posted / ali asghar

As we know

R= p*L/A
if resistance decreased by 10 % it mean new resistance is
L'=0.9L
And Area is increased by 10 % because volume will remain constant so new area will be
A' = 1.1A
so
R'=p* .9L/1.1A =.9R/1.1=0.81R
so change in resistance is = 1-0.81=0.91=0.91*100 %= 19 %
so resistance decreased by 19%

Is This Answer Correct ?    55 Yes 9 No



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