Answer to Question #311315 in Electric Circuits for Jinky

Question

An aluminum wire with a diameter of 1.02 mm and volume of 1.57x10^-5 m³, has a battery attached to it with an emf of 30 volts. Find (a) the resistance of the wire and (b) the corresponding current.

Answer 1

Answer

a) Radius r=0.56mm

Length of wire $l=\frac{volume }{area}$

Resistance of wire is

$R=\rho \frac{l}{A}\\=\frac{2.65*10^{-8}*1.57*10^{-5}}{3.14*3.14*(0.56*10^{-3})^4}\\=0.429\Omega$

b) so current

$I =\frac{30}{0.429}\\=69.93A$