Question

tell this question please

Answer 1

volume of a cylindrical wire=π(d1/2)^2*l1
old diameter=d1
new diameter=d2
old length=l1
new length=l2
atq
d2=d1-5%d1
d2=19d1/20

(π*19d1*19d1*l2)/1600=(π*d1*d1*l1)/4
361d1^2*l2=400d1^2*l1
l2/l1=400/361
l2=400l1/361

increase in length
400l1/361-l1=39l1/361

%increase in length
(39l1/360)/100=3900l1/360
=10.80%increase