Question

Find the resistance of eureka wire 1.1m long and 0.2mm in diameter.Resistivity of eureka=49*10 what is the current flowing through the wire when a potential difference of 1 v is applied across its ends

Answer 1

Answer :

Resistance = 1.715 x 10^-3 ohm

Current = 5.38 x 10^2 A

Explanation :

length of the eureka wire = 1.1m

resistivity of eureka wire = 4.9 x 10^-7 ohm m

Diameter of wire = 0.2mm = 2 x 10^-4 m

Radius, r = 1 x 10^-4 m

Resistance, R = pL/A

A=pie r^2

R = 4.9 x 10^-7 x 1.1 x 7 /22 x 2 x 10^-4

= 1.715 x 10^-3 ohm

V = 1 V

V = IR

I =V/R

= 1/ (1.715 x 10^-3)

I=5.83 x 10^2 A