Download equivalent resistance

Series and Parallel
RESISTORS
EQUIVALENT RESISTANCE

a single resistance that can replace all the
resistances in an electrical circuit while
maintaining the same current when connected
to the same source

symbol Rtotal or Rt
RESISTANCE RULES
by combining KVL, KCL and Ohm’s Law, the
following rules can be derived:
 for any number of resistors connected in series
Rt = R1 + R2 + R3
 for any number of resistor connected in parallel
1/Rt = 1/R1 + 1/R2 +1/R3

SERIES EQUIVALENT RESISTANCE
PRACTICE

Calculate the equivalent resistance in a series
circuit containing the following resistances in
series: 26 Ω, 11 Ω and 18 Ω.

55 Ω
PARALLEL EQUIVALENT RESISTANCE
PRACTICE

Calculate the equivalent resistance of a circuit
with the following resistors in parallel: 5 Ω, 10 Ω
and 30 Ω.

3Ω
PRACTICE

Find the equivalent resistance in the circuits
below:
HOMEWORK
page 339 #4, 5
 page 340 #7
 page 342 #9
