4.3 Electrical circuits checklist

Core

Draw and interpret circuit diagrams containing cells, batteries, power supplies, generators, potential dividers, switches, resistors (fixed and variable), heaters, thermistors (NTC only), light-dependent resistors (LDRs), lamps, motors, bells, ammeters, voltmeters, magnetising coils, transformers, fuses and relays and know how these components behave in the circuit.
Know that the current at every point in a series circuit is the same.
Know how to construct and use series and parallel circuits.
Calculate the combined e.m.f. of several sources in series.
Calculate the combined resistance of two or more resistors in series.
State that, for a parallel circuit, the current from the source is larger than the current in each branch.
State that the combined resistance of two resistors in parallel is less than that of either resistor by itself.
State the advantages of connecting lamps in parallel in a lighting circuit.
Know that the p.d. across an electrical conductor increases as its resistance increases for a constant current.

Draw and interpret circuit diagrams containing diodes and light-emitting diodes (LEDs) and know how these components behave in the circuit.
Recall and use in calculations, the fact that:a)the sum of the currents entering a junction in a parallel circuit is equal to the sum of the currents that leave the junctionb)the total p.d. across the components in a series circuit is equal to the sum of the individual p.d.s across each componentc)the p.d. across an arrangement of parallel resistances is the same as the p.d. across one branch in the arrangement of the parallel resistances.
Explain that the sum of the currents into a junction is the same as the sum of the currents out of the junction.
Calculate the combined resistance of two resistors in parallel.
Describe the action of a variable potential divider.
Recall and use the equation for two resistors used as a potential divider: V₁/R₁ = V₂/R₂