Transcript Resistance in Series Circuits

Ohm’s Law






Resistance in Series Circuits
Resistance in Parallel Circuits
Total Resistance
Equivalent Resistance
Voltage Drops and Resistance
Conductance and Current Flow
Resistance in Series Circuits
Key Point:
In a series circuit the
total resistance equals
the sum of the
individual resistances.
RT = R1 + R2 +. . .+ RN
Resistance in Parallel Circuits
Key Point:
Conductance is the
1 ,R  1
C

reciprocal of resistance.
R
C
In a parallel circuit the
total conductance equals GT = G1 + G2 +…+ GN
the sum of the individual
branch conductances.
Total Resistance
RULE 11-1
To find the total resistance in a series-parallel
circuit:
1. Determine which resistors are in parallel
and reduce that part of the circuit to an
equivalent resistance;
2. Add series resistances when possible;
3. Continue steps I and 2 until the circuit is
reduced to one resistance.
Equivalent Resistance
Voltage Drops and Resistance
Key Point:
In a series circuit the
greater voltage drops
across the greater
resistance.
If R1 > R2, then V1 > V2
Conductance and Current Flow
Key Point:
In a parallel circuit the
greater current flows
If G1 > G2, then I1 > I2
through the greater
conductance.