College Physics PhET Resistivity Simulations EPCC
Goal : Learn about resistivity.
Check the link in figure 1.
Learn more about how a resistor resists cu
ent
ased on its physical characteristics.
Change the following parameters of the resistor
according to the settings below. Remember to
eset the simulation for every case:
1. Vary the length of the resistor, keeping all
things constant
2. Vary the cross-sectional area, keeping all
other things constant
3. Vary the resistivity, keeping all other
things constant
Problems:
1. Make notes on what you learned from this simulation. Write a synopsis (no more than 5
sentences) on what you learned from the simulation.
2. Calculate the maximum and minimum conductivity based on the maximum and minimum
esistance you got from this simulation. What type of relationship does the resistivity has
with conductivity of a material?
Figure 1: PhET simulation on resistivity. Use
this link to access the simulation:
https:
phet.colorado.edu/sims/html
esistance-in-a-wire/latest
esistance-in-a-
wire_en.html
https:
phet.colorado.edu/sims/html
esistance-in-a-wire/latest
esistance-in-a-wire_en.html
https:
phet.colorado.edu/sims/html
esistance-in-a-wire/latest
esistance-in-a-wire_en.html
https:
phet.colorado.edu/sims/html
esistance-in-a-wire/latest
esistance-in-a-wire_en.html
https:
phet.colorado.edu/sims/html
esistance-in-a-wire/latest
esistance-in-a-wire_en.html
College Physics II Resistor configurations EPCC
Objective: Understand how resistors in series and parallel work. The LED bulbs will act as
esistors, while the illuminance from the bulbs will be a proxy for cu
ent intensity in the circuit.
Review Ohm’s law for this lab.
Refer to the laboratory lecture to complete this laboratory.
Note: Measurements must be in MKS units.
Circuits
1. Simple circuit: Replicate the circuit described in figure 1, as well as draw the circuit
diagram for this circuit. Activate the PhyPhox® app and select the “simple” function as
shown in figure 2. Place the phone with PhyPhox running 1.0 cm from the edge of the
circuit. Record the illuminance in table 1.
2. Parallel circuit: Replicate the circuit described in figure 2, as well as draw the circuit
diagram for it. Follow the same procedure to record the illuminance, and record this value
in table 1. Make a note what occurs after you remove one of the bulbs from the circuit.
3. Series circuit: Replicate the circuit described in figure 3, as well as draw the circuit
diagram for it. Follow the same procedure to record the illuminance if you can; record this
value in table 1.
Table 1.
Configuration Illuminance (lux)
Simple Circuit
Parallel
Series
click to
ecord
Figure 1: Screen shot of
PhyPhox® Light function. Select
the 'simple' option and click the
play button to begin recording.
Read off the values illuminance
and record in table 1.
College Physics II Resistor configurations EPCC
Questions (Answer within 3 sentences):
1. How does the parallel circuit relate to the simple-circuit case?
2. Based on the series circuit results, what can you say about the cu
ent needed to light
oth bulbs? Does this explanation fit what you would expect from resistors in series?
(a) (b) (c)
Figure 2: Simple circuit for one LED bulb. (a): A minimum of two conductive strips each a length of 6.0
cm is needed. The battery is placed at the left end, with the corner able to flip to complete the circuit
once the bulb is attached (b). The bulb turns on once the circuit is complete (c).
Figure 3: Parallel circuit: An additional
ulb is placed at the further along the
two conductive strips, fastened with
masking tape.
Figure 4: Series circuit: replace the bulbs
such that they are touching each other,
and the other end of each bulb is
connected to the conductive strip.