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Ohm's law

QuickField simulation example

The example is devoted to Ohm's law for an electric circuit in two versions: direct current and alternating current.

Task type:
Plane-parallel problem of AC magnetics.

Geometry model:
Ohms law electric circuit

Given
Resistor R = 20 Ohm;
Inductance L = 0.02 H;
Current I = 1 A;
Frequency f = 0 Hz; 50 Hz.

Task
Find the voltage drops across the circuit elements L, R and compare them with the analytical solutions

Solution
In QuickField, an electrical circuit can be simulated in AC magnetics and in Transient magnetics modules. To simulate a DC current mode we use the transient problem with the time-constant current source.

Analytical solution* for the direct current:
U(R) = I * R = 1 * 10 = 10 V.
U(L) = 0 V.

Analytical solution for the alternating current:
U(R) = I * R = 1 * 10 = 10 V.
U(L) = I * 2 * π * f* L = 1 * 2 * 3.14 * 50 * 0.02 = 6.28 V.

*Wikipedia: Ohm's law.

Result
Voltage drop calculated by QuickField

DC

V(R) = 20 V,    V(L) = 0 V
Ohm's law DC

AC, 50 Hz

V(R) = 20 V,    V(L) = 6.28 V
Ohm's law AC