Topic 3 - Basic electricity Flashcards
Units
(E) Energy - joules (J)
(Q) Charge - Coulombs (C)
(V) Voltage - Volts (V)
(I) Current - Amps (A)
(R) Resistance - Ohms (Ω)
Equations
- Energy = voltage x charge (E=VxQ), Voltage = energy ÷ charge (V=E÷Q), Charge = energy ÷ voltage (Q=E÷V)
- Charge = current x time (Q=IxT), Current = charge ÷ time (I=Q÷T), Time = charge ÷ current (T=Q÷I)
- Voltage = current x resistance (V=IxR), Current = voltage ÷ resistance (I=V÷R), Resistance = voltage ÷ current (R=V÷I)
- Resistance = voltage ÷ time (R=V÷T), Voltage = resistance ÷ time (V=R÷T), Time = resistance ÷ voltage
Lamp
Cell
Battery
Ammeter
Voltmeter
Resistor
Current- series
The current is the same at all parts in the circuit.
Current- parallel
The total current in the circuit is the sum of the currents through the separate branches. (Current splits at a junction and how the current splits depends on the relative resistance of each branch).
Voltage- series
The total voltage is divided (shared) between the components.
Voltage- parallel
The voltage is the same across each branch in the circuit, and is equal to the voltage of the power supply
Resistance- series
The total resistance is the sum of the separate resistances. As you add more components in series, the total resistance increases and the total current decreases.
Resistance- parallel
The total resistance reduces as you add more components in parallel. The total resistance in a parallel circuit is equal to the sum of the inverse of each individual resistances.
Current
The rate of flow charge