D.C. circuits
Circuit symbols, series and parallel rules, effective resistance and whole-circuit calculations.
Learning goals
- Recognise and interpret circuit symbols for cells, batteries, switches, lamps, LEDs, resistors, fuses, ammeters and voltmeters
- Draw circuit diagrams with cells, batteries, switches, lamps, LEDs, fixed and variable resistors, fuses, ammeters and voltmeters
- Apply the same-current rule in series circuits
- Apply the potential-difference sum in series circuits
- Apply current conservation at parallel junctions
- Apply equal potential difference across parallel branches
- Calculate effective resistance in series
- Calculate effective resistance in parallel
- Solve whole-circuit problems using consistent quantities
G2 Science (Physics) · Topic 11
Read the complete lesson from top to bottom first. Pause for its examples and independent questions, then use a short topic check to decide what to practise again.
Before you begin
Build the idea in order
- Circuit symbols and meters
- Series rules
- Parallel rules
- Whole-circuit calculations
Lessons
D.C. Circuits
Circuit symbols, meter placement, series and parallel rules, effective resistance and whole-circuit calculations.
Check your understanding
D.C. circuits topic check
Check the required topic capabilities and get focused practice for ideas that need another look.
G2 Science Structured Practice — Mixed D.C. Circuits
Calculate source current and component p.d. in mixed resistor networks, correct inconsistent measurements, and account for branch currents.
What to remember
- An ammeter is series and a voltmeter parallel.
- Series current is common and potential differences add.
- Parallel potential difference is common and currents add.
- Series resistances add; parallel reciprocals add.
- V, I and R must describe the same circuit section.
Topic and syllabus information
D.C. circuits is Topic 11 in K223 / K224 Physics component · 2027.
The lesson stays within G2 depth and includes the explanations, examples and practice needed for this topic.
Reviewed 9 Aug 2026
Continue with the next resource in this course.
Course and syllabus information
- Course
- SEC G2 Science Physics component
- Edition
- SEC G2 Science Physics component 2027