D861 Electricity and Magnetism, catalog number PHYS 3010, is the three-CU course on the principles behind electronics, motors and electrical infrastructure. The conceptual hinge is the field. Charges do not act on each other across empty space by magic: a charge alters the space around it, and another charge responds to that alteration where it sits. Once the field is real to you, circuits, magnetism and induction stop being three topics and become three consequences.
Fields first, circuits second
Start with what a field is for. It converts action at a distance into a local story: this charge creates a condition everywhere, and any charge placed somewhere responds to the condition at that point. Potential is the companion idea, describing the energy per unit charge associated with position in that field, which is exactly what a battery's voltage rating means. Students who learn circuits without the field find that voltage remains a mysterious quantity that pushes electricity, and every later question about potential difference across a component becomes guesswork.
Circuits then follow from two conservation statements. Charge does not accumulate at a junction, so what flows in flows out. Energy per unit charge is conserved around any closed loop, so the rises and drops must balance. Every series and parallel result you might otherwise memorise comes out of those two sentences, including why adding a parallel branch lowers total resistance, which is otherwise one of the most counterintuitive facts in the subject.
Magnetism is where the course rewards care. Moving charge produces a magnetic field, magnetic fields exert forces on moving charge, and the geometry is perpendicular rather than parallel, which is why the direction rules exist and why they feel unnatural. Induction closes the story: a changing magnetic flux drives a current, and the induced effect opposes the change that produced it. Motors and generators are the same physics run in opposite directions, and saying so out loud is usually the moment the topic clicks.
Planning the work from your Course of Study
The scoring detail sits in your Course of Study rather than in the public catalog. Read it before building a study plan, because a written deliverable and a proctored exam need different preparation. Where written work is scored, every aspect is judged on its own and needs a 2, and electromagnetism aspects usually separate the calculation from the explanation.
The word budget, worked. Take five scored aspects and directions asking for about 1,500 words. Reserve 110 words for setting up the situation and 90 for a close, leaving roughly 1,300, or 260 an aspect. Then shift 60 words from each descriptive aspect into any aspect asking why a result follows, because in this subject the algebra is compact and the reasoning is what earns the score. A circuit diagram or a field sketch pays for itself in words saved.
The study budget, worked. Around fifty hours. Give twenty-five percent to fields and potential because everything rests on them, twenty-five percent to direct current circuits, twenty percent to magnetic fields and forces, twenty percent to induction and its applications, and ten percent to mixed problems with no topic labels attached. Spend at least half of every block solving rather than reading.
If your program includes practical work, budget separately for it. Building and measuring a circuit takes an evening; debugging one that does not behave takes two.
A study structure that fits electricity and magnetism
This sequence works whether the course is assessed by written work, by a proctored objective assessment or by both.
| Stage | The move | What it prevents |
|---|---|---|
| Sketch the field | Draw field lines and equipotentials before any calculation | Treating voltage as a mysterious pushing quantity |
| Label the circuit | Mark current directions and polarity on the diagram before writing equations | Sign errors that are invisible once the algebra starts |
| Apply the two conservation rules | Junction and loop statements written explicitly for the circuit in front of you | Memorising series and parallel formulas without their basis |
| Check the power | Confirm that power delivered equals power dissipated | Answers that are algebraically neat and physically impossible |
| Use the geometry rules | Practise direction rules until the perpendicular relationships are automatic | Correct magnitudes pointing the wrong way |
| Reason from flux | For induction, ask what flux is changing and how fast, then apply opposition | Guessing the direction of an induced current |
| Connect to devices | Explain a motor, a transformer and a generator in your own words | Formal knowledge that cannot answer an application question |
| Retrieve regularly | Reproduce field patterns and circuit results from memory, then check | Recognition mistaken for understanding under assessment conditions |
Keep a running list of the direction errors you make. In this subject they repeat with unusual consistency, and six lines of personal error history is worth more than any published summary.
Evidence craft when you write about electromagnetism
Written work in this subject is judged on whether a reader can follow the reasoning without reconstructing it.
- State the principle before the equation. Charge conservation at a junction applies here because no charge accumulates.
- Define symbols, directions and reference points, including which terminal you treat as zero potential.
- Draw the circuit or the field and refer to the drawing in the text rather than describing it in prose.
- Carry units through and check the final unit, since dimensional errors in this subject usually signal a misapplied relationship rather than arithmetic.
- Interpret the result physically. A current of 0.4 amperes is a fact; a current that would exceed the component's rating is a finding.
- Where you describe a device, name the physical principle it exploits rather than describing its parts.
- Cite constants, component data and any published values you use, in APA where directions require it.
Where a deliverable asks about real infrastructure, the useful discipline is scale. The physics that governs a bench circuit also governs a transmission line, but the quantities differ by orders of magnitude and the engineering consequences differ with them. Saying so explicitly is what turns a textbook answer into an applied one.
What separates Competent from a return or a retake
Because aspects score alone, the return usually names a direction that was asserted or an explanation that restated the calculation.
- Fields and potentials are used as the basis for circuit reasoning.
- Conservation statements are written for the specific circuit rather than assumed.
- Directions are derived from the geometry rules and shown on a diagram.
- Induction answers identify what flux changed and how fast.
- Units are carried and results are checked against a power balance.
- Device explanations name the principle, not just the components.
Performance assessment work can be revised and resubmitted with no grade penalty, so a return costs calendar time inside a six-month flat-rate term rather than standing. Where any part of the course is assessed by a proctored objective assessment, that exam is yours to sit: we prepare with diagnostics, worked problems and an honest readiness call, and we never ask for portal credentials.
Six mistakes that cost time in D861
- Learning circuit formulas without conservation. The formulas are consequences, and students who memorise them cannot handle a circuit that does not match a template.
- Confusing current and voltage. One is a flow, the other is a difference in energy per unit charge, and the confusion breaks every subsequent analysis.
- Guessing directions. Magnetic force and induced current directions follow from rules that have to be practised until they are automatic.
- Ignoring internal resistance. Real sources have it, and problems that seem inconsistent often become consistent once it is included.
- Skipping the diagram. A labelled sketch prevents most sign errors and takes thirty seconds.
- Reading rather than solving. This is a problem-solving subject and recognition of a worked solution is not the ability to produce one.
How support works on this course
Send your topic list or task directions with whatever your Course of Study says about scoring. What comes back is a diagnostic that separates a field concept problem from an algebra problem from a direction-rule problem, worked circuits with the conservation statements written out, and induction problems approached through flux rather than through pattern matching.
For teacher candidates there is a further payoff. Explaining a motor or a transformer clearly to somebody with no physics is a classroom skill as well as a study check, and it is the fastest way to find out which parts of your own understanding are still verbal rather than physical.
Where a deliverable asks you to analyse a real installation, household wiring, a motor circuit or a section of distribution network, the useful discipline is to state the model you are applying and the simplification it involves before any numbers appear. Real systems carry resistance in the wiring, temperature effects and loads that vary through the day, and a submission that names those and then proceeds with an idealised treatment reads as engineering judgment rather than as an omission.
Questions students ask about D861
Is D861 the same course as PHYS 3010?
Why do parallel resistors reduce total resistance?
How much calculus does D861 require?
Circuits fine until the magnetic directions arrive?
Send your topic list or task directions. You get a diagnostic, worked circuits with conservation written out and induction reasoned from flux rather than guessed.
Where D861 sits in WGU's programs
The July 2026 catalog places this code in 3 current WGU programs. Open a program page for the complete standard path and term positions. The live Degree Plan remains authoritative after transfer credit, substitutions, and mentor planning.
The assessments, one by one
The public catalog does not publish this course's PA/OA identity or task count. WGU Tutors publishes at most one PA manual per course and only from a WGU-controlled public rubric. Until that source exists, PA help begins from the student's real Course of Study and OA support remains preparation only.