← Physics 2 syllabus

United StatesPhysics 2

Unit 11: Electric Circuits

8 dot points across 8 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How do capacitors combine in circuits, and how does an RC circuit charge and discharge over time?

Topic 11.8 Capacitors in Circuits and RC Circuits: combine capacitors in series and parallel and describe charging and discharging through a resistor.
A focused answer to AP Physics 2 Topic 11.8, covering capacitors in series and parallel, the equivalent capacitance rules, the behavior of a capacitor in a circuit at the first instant and after a long time, and the charging and discharging of an RC circuit with its time constant, with full worked examples.
12 min answer →

What is electric current, and how does charge actually flow through a wire?

Topic 11.1 Electric Current: define electric current as the rate of charge flow and relate it to drift of charge carriers.
A focused answer to AP Physics 2 Topic 11.1, covering electric current as the rate of flow of charge, the conventional-current direction, the drift of charge carriers, the distinction between drift speed and signal speed, and the link between current and charge, with full worked examples.
10 min answer →

How fast does a circuit deliver and dissipate energy, and what sets a device's power?

Topic 11.4 Electric Power: calculate the power delivered or dissipated in a circuit using P = IV, P = I squared R and P = V squared over R.
A focused answer to AP Physics 2 Topic 11.4, covering electric power as the rate of energy transfer, the three equivalent power formulas, the power dissipated in a resistor, energy used over time, and how to choose the right formula, with full worked examples.
10 min answer →

Why must all the current arriving at a junction equal all the current leaving it?

Topic 11.7 Kirchhoff's Junction Rule: apply conservation of charge to the currents at a junction in a circuit.
A focused answer to AP Physics 2 Topic 11.7, covering Kirchhoff's junction rule as conservation of charge, how current splits and recombines at junctions, writing junction equations, and combining the junction and loop rules to solve multi-loop circuits, with full worked examples.
10 min answer →

Why must the voltage changes around any closed loop in a circuit add to zero?

Topic 11.6 Kirchhoff's Loop Rule: apply conservation of energy to the voltage changes around any closed loop of a circuit.
A focused answer to AP Physics 2 Topic 11.6, covering Kirchhoff's loop rule as conservation of energy, the sign conventions for emf sources and resistors, how to write loop equations, and its use in multi-loop circuits, with full worked examples.
11 min answer →

What determines a conductor's resistance, and when does current grow in step with voltage?

Topic 11.3 Resistance, Resistivity, and Ohm's Law: apply Ohm's law and relate resistance to resistivity, length and cross-sectional area.
A focused answer to AP Physics 2 Topic 11.3, covering resistance and Ohm's law V = IR, the dependence of resistance on resistivity, length and cross-sectional area, the meaning of ohmic and non-ohmic behavior, and how to read a current-voltage graph, with full worked examples.
11 min answer →

How do resistors combine in series and parallel, and how does that change the current and voltage?

Topic 11.5 Resistors in Series and Parallel: find the equivalent resistance of series and parallel combinations and the resulting currents and voltages.
A focused answer to AP Physics 2 Topic 11.5, covering the equivalent resistance of resistors in series and in parallel, how current and voltage divide in each arrangement, the reasoning behind the combination rules, and how to reduce a network step by step, with full worked examples.
12 min answer →

What makes a circuit complete, and what does a battery actually supply to drive a current?

Topic 11.2 Simple Circuits: interpret circuit schematics and explain the role of emf, the complete circuit and the conventions for open and short circuits.
A focused answer to AP Physics 2 Topic 11.2, covering circuit schematics and their symbols, the complete (closed) circuit, the role of electromotive force as energy per charge supplied by a source, internal resistance and terminal voltage, and open and short circuits, with full worked examples.
11 min answer →