1. ELECTRICAL CIRCUITS
Measurements

2. This is how to draw an ammeter in a circuit.
Measuring current
This is how to draw an ammeter in a circuit. A A
SERIES CIRCUIT
PARALLEL CIRCUIT

3. Measuring current SERIES CIRCUIT at all points in the circuit.
Current is the same
at all points in the
circuit.
The electrons flow single file 2A 2A 2A
PARALLEL CIRCUIT
Current is shared
between the
components
The electrons split up 2A 2A 1A 1A

4. Fill in the missing ammeter readings.
Measuring current
Fill in the missing ammeter readings. 3A ? 3A 4A ? ? 1A 4A ? 4A 1A ? 1A

5. Measuring current Summary Current is “stuff”, actual electrons
In a single file line it must be the same throughout.
In a branched path is must split up, with some down each path 3A ? 3A 4A ? ? 1A 4A ? 4A 1A ? 1A

6. This is how to draw a voltmeter in a circuit.
Measuring voltage
This is how to draw a voltmeter in a circuit. V V
SERIES CIRCUIT
PARALLEL CIRCUIT

7. Voltage is shared between the components
Measuring voltage
Series Circuit
Voltage is shared between the components
Like a train running through brick walls. It slowly comes to a stop 6V 3V 3V

8. Voltage is the same in all parts of the circuit.
Measuring voltage
Parallel Circuit
Voltage is the same in all parts of the circuit. 3V
Like two people under the same waterfall 3V 3V

9. Review a) 6V 4A A V V A

10. Review b) 6V 4A A V A V A

11. Review
Answers a) b) 6V 6V 4A 4A 6V 4A 4A 3V 3V 2A 4A 6V 2A

12. Review Summary Current Voltage
In a series circuit, the current is the same throughout
In a parallel circuit the current divides up amongst all the paths
Voltage
The opposite of current
In a series circuit it is divided up amongst each element
In a parallel circuit each “person under the waterfall” receives the same voltage