Summary Grade 12: Electric Circuits

ELECTRIC
CIRCUITS

, ELECTRIC CIRCUITS
Electric circuits
- need an electric circuit for current to flow
- Types of components:
Source that supplies energy for the flow of current
Conducting material through which current can flow
Appliance -> converts electrical energy to heat and light
- Current direction: positive -> negative (conventional current)
- Types of circuits:
Series connection: they are sequentially connected in a way that creates a single path
Parallel connection: Multiple pathways


Circuit diagrams
CELL & BATTERY SWITCH CONDUCTOR
Provides energy for charges Closes or opens circuits Connects circuit elements
to move Symbol: Symbol:
open
Symbol: AMMETER
closed Measures the current in a
circuit ( I )
BULB RESISTOR VOLTMETER Symbol: A
Glows when current flows Resists the flow of charge Measures potential
through it Symbol: ( R ) difference ( V )
Symbol: Symbol: V



potential difference
- Def: The work done per unit positive charge FORMULAS
- in the cell: stored chemical potential energy -> electrical potential
energy
- when charges leave the positive terminal = high electrical potential V W
energy
- Measurement = volts measured by a voltmeter: R I V Q-



always connected in parallel
has a high resistance, in parallel it won't affect the flow of 1 Volt = 1 Joule
current 1 Coulomb
Must have a high resistance in comparison with other components
POTENTIAL DIFFERENCE IN SERIES AND PARALLEL
V V BATTERIES
- Chemical -> electrical
SERIES X PARALLEL - Connected in series = larger current = larger internal resistance
X X V - When battery is flat: chemical cells in cell = completed
V V
X Cell = flat = higher internal resistance
V