Circuits, current and electromagnetism
≈ 48 minCircuits, current and electromagnetism
A circuit model links charge flow, potential difference, resistance and energy transfer. Current is rate of charge flow and is measured in amperes; potential difference is energy transferred per unit charge and is measured in volts. Ohm's law, V = IR, relates these quantities for an ohmic conductor under constant physical conditions. In a series circuit, the same current passes through each component; in a parallel circuit, each branch has the same potential difference as the supply. A current-carrying conductor produces a magnetic field, and changing a magnetic field can induce a potential difference. Draw a clear circuit and identify the component or branch being discussed before using an equation.
Work it through
A 6.0 Ω resistor connected to a 12 V supply has I = V/R = 12/6.0 = 2.0 A. If another resistor is added in series, total resistance rises and the circuit current falls. If a similar resistor is added in parallel, total resistance falls because charge has an additional path. The circuit diagram is part of the evidence, not decoration.
Mastery target
Analyse a simple circuit using V = IR, distinguish series from parallel behaviour and explain the link between current and magnetic effects.
What is the current through each component in a simple series circuit?
Name the key physics term from Circuits, current and electromagnetism that best fits the explanation and visual model.
What current flows through a 6.0 Ω resistor connected to 12 V?
Which statement corrects a common misunderstanding in Circuits, current and electromagnetism?