Electric circuits — Grade 12 Past Paper Questions

Identify the relationship between voltmeter readings in a circuit containing three resistors, an emf source with internal resistance, and multiple voltmeters measuring potential differences across different circuit elements.

Analyze a multi-resistor circuit with switches using ammeter and voltmeter readings to find unknown resistances where one resistor is twice another, calculate power dissipation, and predict ammeter readings for different switch configurations.

Apply Ohm's law to analyze a circuit with unknown emf and internal resistance, using multiple switches and ammeters to calculate voltmeter and ammeter readings, power dissipation across resistors, and voltmeter response to circuit changes.

Predict how ammeter and voltmeter readings change when a switch closes in a circuit containing identical parallel resistors and a battery with unknown emf and internal resistance.

Calculate the total external resistance and ammeter reading in a circuit with a 12 V battery having 0.30 Ω internal resistance and multiple resistors, determine current through specific resistors, and find voltmeter readings between designated points.

Using ammeter readings and power dissipation data, determine the internal resistance of a 12 V battery, calculate voltmeter readings with the switch open and closed, and analyze how connecting a wire between two points affects voltmeter readings.

Compare the brightness of identical light bulbs arranged in series and parallel configurations with identical batteries, and determine how adding a bulb in parallel affects the brightness of the existing bulbs.

Determine unknown resistor and internal resistance values in a 24 V circuit using ammeter readings and power dissipation calculations, then compare potential differences and analyze how power changes when the switch opens.

Apply Ohm's law to calculate the unknown emf and internal resistance of a battery using voltmeter readings with different switch configurations in a circuit containing known and unknown resistances.

Analyze current distribution in a 24 V circuit with a light bulb and unknown resistor, using different switch combinations to determine ammeter readings and how switch configuration affects bulb brightness.

Compare the resistances of three copper wires by analyzing their respective voltage-current graphs to determine which wire has the greatest resistance.

Extract the emf and calculate the internal resistance of a battery by analyzing a potential difference versus current graph obtained from experimental circuit measurements.

Determine which ammeter shows the lowest reading in a parallel resistor circuit, and identify whether an illustrated machine with poles and rotating coil is a DC motor, AC motor, DC generator, or AC generator.

Calculate the electrostatic force on a charged sphere after contact with another sphere, and determine the power dissipated in one identical resistor given the power in another under specific circuit arrangement.

Determine the voltmeter reading in an open-switch circuit, then predict how ammeter and voltmeter readings change when the switch is closed in a battery circuit with internal resistance.

Identify the magnitude of electrostatic force exerted on one charged sphere by another, and determine which voltmeter connected across identical resistors will show the highest reading.

Identify which voltmeter readings produce specific voltage-current graphs in a battery circuit with internal resistance, and explain how a split-ring commutator ensures continuous motor rotation by managing current direction.

Predict how ammeter and voltmeter readings respond when a switch opens in a circuit with negligible internal resistance, and identify which factors increase the magnitude of induced emf in an AC generator.