Physics: At room temperature, what is the strength of the electric field in a 12 gauge copper wire (diameter 2.05 mm) that is needed to cause a 4.70 a current to flow? use the resistivity at room temperature for copper rho = 1.72×10−8 ω⋅m.

At room temperature, what is the strength of the

lukeperry

10.01.2022

Electric field will be $2.33\times 10^{-2}V/m$

Explanation:

We have given diameter of the copper d = 2.05 mm

So radius $r=\frac{d}{2}=\frac{2.05}{2}=1.05mm=1.05\times 10^{-3}m$

We know that area $A=\pi r^2=3.14\times (1.05\times 10^{-3})^2=3.461\times 10^{-6}m^2$

Current is given as i = 4.7 A

So current density $j=\frac{i}{A}=\frac{4.70}{3.461\times 10^{-6}}=1.357\times 10^6A/m^2$

Resistivity is given $\rho =1.72\times 10^{-8}ohm-m$

We know that electric field is given by $E=\rho j=1.72\times 10^{-8}\times 1.357\times 10^6=2.33\times 10^{-2}V/m$

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adriannamartinez000

15.11.2020

The correct answer is c

Explanation:

Flow is defined by

Ф = B . A

bold letters indicate vectors.

The magnetic field is directed to the y axis, The area of the coil is represented by a vector normal to the plane of the coil, so to have a flux

i.i = j.j = k.k = 1

and the tori scalar products are zero

a) If the coil must be in the xy plane so that its normal vector is in the Z axis, so there is no flux

b) if the coil is in the plane yz the normal veto is in the x axis, so the flux is zero

C) If the coil is in XZ, the normal vector points in the y direction, usually the scalar product is one and there is a flux in this configuration

The correct answer is c

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