Transcript Complex Resistor Combinations

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.