Technical data

46
arallel Circuits
etecting a Short in a Parallel Circuit
roject Objective:
To provide experience with resistance changes that occur when a short develops in a parallel
circuit.
ems Needed:
- Electronics Trainer - Digital multi-meter
- Jumper Wires - Resistors: 47k, 100k, 220k
o not use the power supply for this project!
P
D
P
It
D
xperiment E
1. Connect the circuit as shown in Figure 20-1.
2. Using an ohmmeter, measure between points A and B
to find the total resistance of the circuit. Remember,
there is to be no power applied to the circuit when
making resistan
ce measurements!
1
becoming shorted by removing it and
jumper wire. Measu
____.
anch of a parallel circuit is shorted,
R
T
(increases, decreases) ________________
wer supply, assume there is 10v applied between
ugh
R
2
? __________________.
_____________.
ould the voltage reading be across
R
2
? ____________
circuit. Use the assumed 10v applied and
e power supply?
______________
4.
__________________________
__________
to
rrent through the “un-shorted” branch increase or decrease?
_______________
R
T
= _________________________.
3. Simulate
R
replacing it with a re the new
R
T
and record the result below.
New R
T
= _____________________
When a br
to ________ . Without connecting the po
points A and B. How much current would be going thro
How much current would be going through R
3
? _____
With the assumed 10v applied, what w
Across R
3
? ____________.
Assume there is 0.01 of resistance in the shorted
calculate the circuit current using Ohm’s Law.
I
T
= ________________.
Would this be enough current to blow the fuse on th
Remove the jumper wire and place
R
1
back into the circuit. Now simulate a short in branch R
2
by replacing resistor
R
2
with a jumper wire. Measure and record R
T
again.
R
T
= .
A short in any branch of a parallel circuit will cause R
T
to _____________
________ .
Does the cu
Figure 20-1
47k
220k
100k
R
1
R
2
R
3
A
B