Current and Voltage in series circuits
Voltage is measured in volts (V) .eg. 9V, 12V, 10V
Resistance is measured in ohms (Ω) .eg. 1 Ω , 10 Ω , 100 Ω ,100 k Ω
Current is measured in amps (A) .eg. 2A, 5A, 10A
The circuit has to be closed for current to flow through it.
Current does not flow through an open circuit.
Note:
1. When you measure resistance, you ALWAYS disconnect the battery or supply from the circuit.
2. Voltmeters are ALWAYS connected in parallel.
CHARACTERISTICS OF SERIES CIRCUITS
- Current flows one way through components
- Circuit is one continuous loop
- The loop starts at the power supply and ends back at the power supply
- If there is a break in the circuit, current stops flowing to ALL components
- When current flows through a component, a voltage appears across it.
- The voltage is shared between the components.
- The total current It = I1= I2 = I3 Eg. It = 0.5 = 0.5 = 0.5A (Fig. 2)
- The total voltage Vt = V1 + V2 +V3 Eg. Vt = 10+15+5 = 30V (Fig. 3)
Resistance is measured in ohms (Ω) .eg. 1 Ω , 10 Ω , 100 Ω ,100 k Ω
Current is measured in amps (A) .eg. 2A, 5A, 10A
The circuit has to be closed for current to flow through it.
Current does not flow through an open circuit.
Note:
1. When you measure resistance, you ALWAYS disconnect the battery or supply from the circuit.
2. Voltmeters are ALWAYS connected in parallel.
CHARACTERISTICS OF SERIES CIRCUITS
- Current flows one way through components
- Circuit is one continuous loop
- The loop starts at the power supply and ends back at the power supply
- If there is a break in the circuit, current stops flowing to ALL components
- When current flows through a component, a voltage appears across it.
- The voltage is shared between the components.
- The total current It = I1= I2 = I3 Eg. It = 0.5 = 0.5 = 0.5A (Fig. 2)
- The total voltage Vt = V1 + V2 +V3 Eg. Vt = 10+15+5 = 30V (Fig. 3)
Current and Voltage in parallel circuits
CHARACTERISTICS OF PARALLEL CIRCUITS
- Current flows through branches with components
- Circuit has various continuous loops
- If there is a break in one branch of the circuit, current does NOT stop flowing through the rest of the circuit.
- When current flows through a component, a voltage appears across it.
- The voltage is the same for ALL parallel components.
- The current is shared between ALL parallel components.
- The total current It = I1+ I2 + I3 Eg. It = 0.1 + 0.1 + 0.1 = 0.3A (Fig. 2)
- The total voltage Vt = V1 = V2 =V3 Eg. Vt = 1.5=1.5=1.5 = 1.5V (Fig. 1)
CHARACTERISTICS OF PARALLEL CIRCUITS
- Current flows through branches with components
- Circuit has various continuous loops
- If there is a break in one branch of the circuit, current does NOT stop flowing through the rest of the circuit.
- When current flows through a component, a voltage appears across it.
- The voltage is the same for ALL parallel components.
- The current is shared between ALL parallel components.
- The total current It = I1+ I2 + I3 Eg. It = 0.1 + 0.1 + 0.1 = 0.3A (Fig. 2)
- The total voltage Vt = V1 = V2 =V3 Eg. Vt = 1.5=1.5=1.5 = 1.5V (Fig. 1)