Complex Resistor Combinations Pg 746 752 Ch 20

Complex Resistor Combinations Pg. 746 -752 Ch. 20 -3

Complex Resistor Combinations • Rare to encounter only series or only parallel in circuits • Generally both are combined

Complex Resistor Combinations • ex- homes → a fuse/circuit breaker in series with multiple outlets in parallel to each other → allows identical potential difference but safety from overload of current

Complex Resistor Combinations • In series with circuit: • fuse - small metallic strip that melts when current becomes too high. → Replacement necessary when melted • circuit breaker - device that triggers a switch to open circuit when current is too high → reset switch when opened • both are specially designed for specific amounts of current

Complex Resistor Combinations → To find Req for a complex circuit 1. Simplify circuit into groups of series and parallel resistors 2. Find Req for each group Work backwards to find current in and potential difference an individual resistor or lamp or component

Complex Resistor Combinations • Steps for Finding Req in a Complex Circuit • 1. Redraw the circuit as a group of resistors along one side of the circuit. • 2. Identify components in series and calculate their Req • 3. Identify components in parallel and calculate their Req • 4. Repeat steps 2 and 3 until all resistors in circuit are reduced to a single Req • 5. Redraw the circuit using the final Req connected to the original emf source.