ELECTRICAL CIRCUIT LABORATORY
Experiment No. (3)
Parallel DC Circuits
Objective
The focus of this exercise is an examination of basic parallel DC circuits
with resistors. A key element is Kirchhoff’s Current Law which states
that the sum of currents entering a node must equal the sum of the
currents exiting that node. The current divider rule will also be
investigated.
Theory Overview
A parallel circuit is defined by the fact that all components share two
common nodes. The voltage is the same across all components and will
equal the applied source voltage. The total supplied current may be found
by dividing the voltage source by the equivalent parallel resistance. It
may also be found by summing the currents in all of the branches. The
current through any resistor branch may be found by dividing the source
voltage by the resistor value. Consequently, the currents in a parallel
circuit are inversely proportional to the associated resistances. An
alternate technique to find a particular current is the current divider rule.
For a two resistor circuit this states that the current through one resistor is
equal to the total current times the ratio of the other resistor to the total
resistance.
Equipment
(1) Adjustable DC Power Supply
(1) Digital Multimeter
(1) 1 kΩ __________________
(1) 2.2 kΩ __________________
(1) 3.3 kΩ __________________
(1) 6.8 kΩ __________________
