Circuits
A circuit is a closed path that lets charge move while electric potential energy is transferred between sources and components.
How do voltage, resistance, and current describe one moving-charge system?
Voltage describes energy transferred per charge. Current measures charge flow. Resistance connects the two by describing how strongly the component opposes that current.
Ohm's law relates the state of an ideal resistor. Power tells how quickly electrical energy is transferred.
Turn the source up or throttle the path.
The source establishes a potential difference. In a complete circuit, that electric condition drives charge already present throughout the conductor.
At fixed voltage, larger resistance means smaller current. The current is a system response, not a fixed amount supplied by the battery.
For a simple resistive load, higher electrical power means energy is being transferred to thermal and radiant forms more quickly.
Charge flow is continuous around a steady series loop. Components transfer energy, but charge itself is conserved.
Voltage is a potential difference. A single-point voltage only makes sense after choosing a reference potential.
Current tells how much charge crosses per second; voltage tells energy per charge. Their product gives energy transferred per second.