Series and Parallel Resistances  a Summary
To summarize all that we have just learned:
There are 2 types of circuits.... Series and Parallel.
 Series Circuits
 Are connected in a straight line, like a chain.
 All current remains the same throughout the circuit.
 There can be many different voltages in a series circuit, as a voltage drop appears across every resistor.
 The total voltage in a series circuit is equal to the sum of all the individual voltage drops within the circuit.
 The total resistance in a series circuit is equal to the sum of all the individual resistances within the circuit.

The formula for Resistance in Series is:

R
_{
Total
}
= R
_{
1
}
+ R
_{
2
}
+ R
_{
3
}
+ etc...

I
_{
Total
}
= I
_{
1
}
=I
_{
2
}
=I
_{
3
}
etc...

E
_{
Total
}
= E
_{
1
}
+ E
_{
2
}
+ E
_{
3
}
+ etc...

Parallel Circuits
 Are connected allowing multiple paths for current flow.
 All voltage remains the same throughout the circuit.
 There can be many different currents in a parallel circuit, as each leg has the same voltage, but can have a different resistance.
 The total current in a parallel circuit is equal to the sum of all the individual currents on each leg of the circuit.

The formula for Current in Parallel is:

I
_{
RTotal
}
= I
_{
R1
}
+ I
_{
R2
}
+ I
_{
R3
}
+ etc...
 Resistance is found by reciprocating the sum of the reciprocals of the resistance of the individual branches

The formula for Resistance in Parallel is:

1

1 1 1 1 1
 +  +  +  +  +
R _{ 1 } R _{ 2 } R _{ 3 } R _{ 4 } R _{ X... }

E
_{
Total
}
= E
_{
1
}
=E
_{
2
}
=E
_{
3
}
etc...
 Ohm's Law states that there is a relationship which exists between current, resistance, and voltage, such that E = I x R