Technical data

42
arallel Circuits
ower in a Parallel Circuit
roject Objective:
• To verify that the power dissipation in a parallel branch is inverse to that branch’s resistance
value.
• To verify that total power in a parallel circuit is equal to the sum of all the individual branch
power dissipations.
ems Needed:
- Electronics Trainer - Digital multi-meter
- Jumper Wires - Resistors: 2 - 10k, 18k, 47k
ake sure power supply is off when connecting meters or changing circuit components.
xperiment
P
P
P
It
M
E
1. Connect the circuit as shown in Figure 18-1.
2. Apply 12 volts to the circuit. Break the
appropriate “X 18-1 to measure each
circuit at the
of
ts. Record the results below.
_______________________.
it current is equal t ividual
.
otal power in a resistive circuit can be calculated as
_______________ times
_______________ it is _____________ mW.
ces.
P
3
= _________________________
Does
P
T
in step 2? _______________________
hich resistor dissipates the most power? __________ Is this the largest
________ _____
” in Figure
the branch curren
I
1
= ____________________________.
I
2
= ____________________________.
I
3
= _____
al circuSince the tot o the ____________________ of the ind
branch currents, the total current for this circuit must be ____________________ mA
Since the t
, then the total power dissipated by this circu
3. Calculate the individual power dissipations of the three branch resistan
P
1
= __________________________
P
2
= __________________________
P
1
+ P
2
+ P
3
equal the answer given for
_____________W
or the smallest value resistor in the circuit?
___ _______
hich resistor dissipates the least power? _______________________ Is this the largest W
or the smallest value resistor in the circuit?
_______________________
conclusion, the smaller a branch resistance is in a parallel circuit, the (lesser, greater) In
_______________________ amount of power it will dissipate. The voltage through each
Figure 18-1
+
_
10k
47k
18k
V
A
R
1
R
2
R
3