Complete Question
A 10 gauge copper wire carries a current of 20 A. Assuming one free electron per copper atom, calculate the drift velocity of the electrons. (The cross-sectional area of a 10-gauge wire is 5.261 mm2.)
mm/s
Answer:
The drift velocity is 
Explanation:
From the question we are told that
The current on the copper is 
The cross-sectional area is
The number of copper atom in the wire is mathematically evaluated

Where
is the density of copper with a value 
is the Avogadro's number with a value 
Z is the molar mass of copper with a value 
So
Given the 1 atom is equivalent to 1 free electron then the number of free electron is

The current through the wire is mathematically represented as

substituting values

=> 
Answer:
Explanation:
E₀ = 229.1 V/m
E = E₀ / √2 = 229.1 / 1.414 = 162 V/m
B = E / c ( c is velocity of em waves )
= 162 / (3 x 10⁸) = 54 x 10⁻⁸ T
rate of energy flow = ( E x B ) / μ₀
= 162 x 54 x 10⁻⁸ / 4π x 10⁻⁷
= 69.65 W per m².
A solenoid hope this is right