Download Parallel Circuits

Chapter 23
Series & Parallel
Circuits
Series Circuit
•A circuit with only
one path
Parallel Circuit
•A circuit with
several paths for
current flow
Series Circuit
•The current is
constant
•I = constant
Parallel Circuit
•The voltage is
constant
•V = constant
Series Circuit
•The voltage drop is
the sum of individual
voltage drops
•VT = V1 + V2 + V3
Parallel Circuit
•The total current is
the sum of the
currents for each path
•IT = I1 + I2 + I3
Series Circuit
•The total resistance is
the sum of individual
reisitances
•RT = R1 + R2 + R3
Series Circuit
•The current = voltage
over the sum of
individual resistances
•I = V/(R1 + R2 + R3 )
Parallel Circuit
•1/RT = 1/R1 + 1/R2
etc
Ammeter
•A device with tiny
resistance that
measures current in
any part of a circuit
Ammeter
•Must be places in
series with the circuit
to measure the
current.
Volt Meter
•A device with tiny
resistance that
measures voltage in
any part of a circuit
Volt Meter
•Must be places
parallel with the
circuit to measure the
voltage.
Fuse
•A fuse or circuit
breaker protects
against dangerously
high current
Ground-fault
Interrupter
•Opens a circuit where
a shock hazard exists
Short Circuit
•A circuit with very
low resistance
A current of 12 A flows
through a 120 V series
circuit has resistors of 1.0
W, 2.0 W, 3.0 W, & X W.
Calculate:
Rx, V1, V2, V3, & Vx
A current flows through a
120 V parallel circuit has
resistors of 1.0 W, 2.0 W,
3.0 W, & 4 W. Calculate:
RT, I1, I2, I3, I4, & IT
Problems
Calculate the following:
• R1 =
Work problems 1 – 4
on P 404 & 405 in the
classroom set of
Physics books.
Work problems 5 - 10
on P 406 - 408 in the
classroom set of
Physics books.
Work problems 11 15 on P 410 & 411 in
the classroom set of
Physics books.
Work problems 16 18 on P 414 & 415 in
the classroom set of
Physics books.
Answer the questions
on P 417 & 418 in the
classroom set of
Physics books.
Work problems A on
P 418 - 420 in the
classroom set of
Physics books.