We go through solving a circuit which only containes independent sources: two voltage sources and two current sources. KVL and KCL are used to determine voltages and currents.
Determine the amount of power absorbed or supplied by each source.
1) Ideal Independent Voltage Sources
An ideal independent voltage source is a two-terminal circuit element where the voltage across it
a) is independent of the current through it
b) can be specified independently of any other variable in a circuit.
There are two symbols for ideal independent voltage source in circuit theory:
Solution
a) The current source keeps the current of the loop and the voltage source keeps the voltage across the current source as shown below. (more…)
Find the current passing through the voltage source:
a)
b)
Solution
a) The voltage source is in series with the current source. Since by definition a current source keeps the current passing through itself constant and the voltage source is in series with the current source, it should have the same current . (more…)
and power absorbed or supplied by each element.
, 
, 
, 
,
,
is in series with the current source; therefore, the same current passing through it as the current source:
and 
using voltage division rule.
, 
, 
, 
and 
and the voltage source keeps the voltage across the current source 
as shown below.
.
and 
. (Hint: there is no need to use nodal analysis; voltages between nodes can be easily found by the voltage sources.)
.