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Engineering StudiesTVET College30 min

Basic Electrical Circuits: Series and Parallel

Series vs parallel circuits and Ohm's law — the foundation of electrical trade and engineering studies.

Electricity needs a loop

A circuit is a complete path for electric current: energy source → conductor (wires) → load (lamp, resistor) → back to the source.

Series circuits

One path only. The same current flows through every component. Voltages add up: Vtotal = V₁ + V₂. Remove one lamp — the whole circuit goes dark (old-style Christmas lights!).

Parallel circuits

Multiple branches. Each branch gets the full supply voltage; currents add up. Remove one lamp — the rest keep working. That's why your house is wired in parallel.

Ohm's law

V = I × R — voltage (volts) = current (amperes) × resistance (ohms). Also I = V/R and R = V/I.

Worked example

A 12 V battery drives a 4 Ω resistor: I = V/R = 12/4 = 3 A.

Safety first

Never work on a live circuit; use insulated tools; treat every circuit as live until tested dead. On TVET courses: always follow your workshop's safety procedure.

Practise

  1. Find I if V = 230 V and R = 46 Ω.
  2. Two 6 Ω resistors in series — total resistance?
  3. Why are homes wired in parallel?

Watch the video to see both circuit types in action.

Follow along (device voice)

Listen and follow along as each word is spoken

Electricity needs a loop A circuit is a complete path for electric current: energy source → conductor wires → load lamp, resistor → back to the source. Series circuits One path only. The same current flows through every component. Voltages add up: Vtotal = V₁ + V₂. Remove one lamp — the whole circuit goes dark old-style Christmas lights . Parallel circuits Multiple branches. Each branch gets the full supply voltage; currents add up. Remove one lamp — the rest keep working. That's why your house is wired in parallel. Ohm's law V = I × R — voltage volts = current amperes × resistance ohms . Also I = V/R and R = V/I. Worked example A 12 V battery drives a 4 Ω resistor: I = V/R = 12/4 = 3 A . Safety first Never work on a live circuit; use insulated tools; treat every circuit as live until tested dead. On TVET courses: always follow your workshop's safety procedure. Practise 1. Find I if V = 230 V and R = 46 Ω. 2. Two 6 Ω resistors in series — total resistance? 3. Why are homes wired in parallel? Watch the video to see both circuit types in action.