Series Circuit : Series Circuit The current is the same everywhere in this type of circuit.
Example of this is the old type of Christmas lights, when one went out, they all went out.
The sum of the voltage drops across the resistors in a series circuit is equal to the potential difference across the voltage source.
Req=R1 + R2 + R3
Parallel Circuit : Parallel Circuit Is like a branched circuit.
The voltage drops across all branches of a parallel circuit are the same.
So if one light bulb goes out the rest stay on.
1/Req= 1/R1 + 1/R2 + 1/R3
Ammeter : Ammeter Used to measure current in a circuit
Connected in series
Voltmeter : Voltmeter Used to measure the potential difference across any part of a circuit or across the entire circuit.
Is always connected in parallel.