Answer:
3.64×10⁻² cm or 3.64×10⁻⁴ m
Explanation:
Current density = Current/cross sectional area.
δ = I/A................. Equation 1
Where δ = current density, I = current, A = cross sectional area of the wire.
make A the subject of the equation
A = I/δ............. Equation 2
Given: δ = 440 A/cm², I = 0.46 A
Substitute into equation 2
A = 0.46/440
A = 1.045×10⁻³ cm²
But,
A = πd²/4................ Equation 2
Where d = diameter of the wire
make d the subject of the equation
d = √(4A/π)................ Equation 3
Given: A = 1.045×10⁻³ cm², π = 3.14
Substitute into equation 3
d = √(4×1.045×10⁻³/3.14)
d = √(1.33×10⁻³)
d = 0.0364 cm
d = 3.64×10⁻² cm or 3.64×10⁻⁴ m
