Final answer:
The electric field strength in the wire is 25,453 N/C.
Step-by-step explanation:
The electric field strength in a wire can be calculated using the formula E = I/(πr^2), where E is the electric field strength, I is the current, and r is the radius or half the diameter of the wire.
In this case, the diameter of the copper wire is 1.0mm, so the radius is 0.5mm or 0.0005m. The current is 20A. Plugging these values into the formula, we get:
E = 20A/(π * (0.0005m)^2)
E ≈ 25,453 N/C