Ohm's law - QuickField simulation example

The example is about the Ohm's law for an electric circuit. Two cases are simulated: direct current and alternating current.

Engineering question

How to find ohms law circuit voltage drop?

Engineering answer
Set up a plane-parallel QuickField AC Magnetics problem for an Ohm’s law circuit and evaluate voltage drop from computed field results.

Download

Download simulation files (files may be viewed using any QuickField Edition).

Simulation problem

Problem Type
Plane-parallel problem of AC magnetics.

Geometry

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

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