Answer:A) Current = 1.739A, B)current density, J = 2.147x10^6 A/m2
magnitude of electric field , E = 0.036 N/C
)rate of thermal energy, P =2.086W
Explanation:
Resistance = R = ρL/A
But the cross-section area of the wire. is given as
Diameter / 2 = 0.04/2 =0.02in to m = 0.02 / 39.37= 0.000508
A = πr^2 = π x 0.000508^2 = 8.10 x 10^-7
since resistivity of copper,ρ= 17x10-9 ohm.m
so resistance is R = ρL/A
17x10-9 x 33 / 8.1x10-7
= 0.69 ohm.
A) Current = I = Voltage /Resistance =1.20/0.69 =1.739A
B)current density, J = Current /Area
= 1.739/8.1x10-7
= 2.147x10^6 A/m2
c)magnitude of electric field , E = Current density x resistivity =J ρ
E = 2.147 x 10^6 x 17 x 10^-9
E = 0.036 N/C
D)rate of thermal energy, P = I² R =1.739² X 0.69
=2.086W
