A 0.97 V potential difference is maintained across a 1 m length of tungsten wire that has a cross-sectional area of 0.86 mm2 . What is the current in the wire? The resistivity of the tungsten is 5.6 × 10−8 Ω · m . Answer in units of A.

The current throught the wire has a value of 15 A.

Explanation:

We can use Ohm's second law to find the resistance of the wire and then use his first law to find the current in it.

Ohm's second law is given by:

R = (p*l)/A

Where R is the resistance of the wire, A is the area of the cross-sectional, l is the length of the wire and p is the resistivity of the material.

R = [1*5.6*10^(-8)]/(0.86*10^(-6)) = 6.51*10^(-2) Ohms

Ohm's first law is given by:

I = V/R

Where I is the current through the wire, V is the voltage drop across it's terminals and R is it's resistance. We have:

I = 0.97/[6.51*10^(-2)] = 0.15*10^(2) A = 15 A

The current throught the wire has a value of 15 A.