Question

calculate the resistance of 1 metre of copper wire that has a cross-sectional area of about 2 into 10 minus 2 cm square to compare the value of resistance​

Answer 1

Length of the wire (L) = 1km

1km = 1000 m

= 10^3 m.

Area of cross section (A) = 2 x 10^-2cm

it will convert into meter.

We know that,

1 m = 100cm

= 2 x 10^-2/100

= 2 x 10^4m.

Resistivity of the copper (p) = 1.62 x 10^-8

We have to find,

Resistance of the copper wire (R) = ??

We know that,

R = p L/A

So,by putting the values we get,

R = 1.62 x 10^-8 x (10^3)/2 x 10^-4

R = 0.081 Ohm .

Therefore, the resistance of the copper is 0.081 Ohm.