Question

A 1.35 V potential difference is maintained across a 1.1 m length of tungsten wire that has a cross-sectional area of 0.72 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.

Answer 1

Answer:

Therefore,

The current in the wire is 15.77 Ampere.

Explanation:

Given:

Length = l = 1.1 meter

V = 1.35 Volt

$Area = 0.72\ mm^{2}=\dfrac{0.72}{1000000}=0.72\times 10^{-6}\ m^{3}$

To Find:

Current, I =?

Solution:

Resistance for 1.1-m long tungsten wire with a cross sectional area, if it is connected across a 1.35 V potential difference given as

$R=\dfrac{\rho\times l}{A}$

Where,

R = Resistance

l = length

A = Area of cross section

$\rho=Resistivity=5.6\times 10^{-8}\ ohm-meter$

Substituting the values we get

$R=\dfrac{5.6\times 10^{-8}\times 1.1}{0.72\times 10^{-6}}=8.56\times 10^{-2}\ ohm$

Now by Ohm's Law,

$I=\dfrac{V}{R}$

Substituting the values we get

$I=\dfrac{1.35}{8.56\times 10^{-2}}=15.77\ Ampere$

Therefore,

The current in the wire is 15.77 Ampere.