Download Response of Circuit Elements

PHY133/123L
Response of Circuit Elements Pre-lab
This Pre-Lab is worth DOULBE.
Name
Please start this pre-lab early and ask questions if you don’t know how to draw a tangent line.
1.
(½)
a.
b.
c.
d.
Each different line in the graph to the right represents?
a fixed resistor
tungsten filament at 1 Hz
a diode in either direction
a conductor, standard copper wires.
Ohm’s law
V = IR
or
I = (1/R) V
If a part of a graph has a changing slope,
that part of the graph is considered to be
(a) dynamic
(b) static
y = m
V = R
x + b
I + 0
Figure 1  
y = m x + b
I = (1/R) V + 0
Current (mA)
vs Voltage (V)
A wire with a potential difference across it is
(a) hot or heating up.
(b) It remains cold, electrical current doesn’t
heat wires.
For the rest of the lab we reverse these
axes. This contradicts the graphing
convention of dependent versus independent
variables. Why would we do this in physics?
Figure 2
   
Volts vs current
Frequency response line of a Tungsten filament.
2.
(½)
a.
b.
c.
d.
Why is this a curved line?
The voltage varies when current changes
The current varies when voltage changes
The resistance changes as voltage varies
All of the above
As in the lab…draw a tangent line at the point of interest; determine resistance from the calculated slope for #4, 6, 8.
3.
(½) A high resistance that changes with
voltage generally corresponds with a
a. cold static resistance
b. hot static resistance
c. hot dynamic resistance
d. small slope
e. cold dynamic resistance
5.
(¼) At 0.1 to 0.3 Volts, the slope
corresponds with
a. hot static resistance
b. hot dynamic resistance
c. cold static resistance
d. cold dynamic resistance
6.
(1) Approximately, what is the maximum hot resistance
a. 48 Ω
b. 26 Ω
c. 2.8 Ω
d. 4.2 mΩ
e. 700 mΩ
f. 1.3 Ω
7.
(¼) At the lower left hand corner of the
oscilloscope the slope represents
a. smaller dynamic resistance
b. higher dynamic resistance
c. cold static resistance
d. low static resistance
e. hot static resistance
8.
(1) Approximately, what is the cold dynamic resistance?
a. 48 Ω
b. 26 Ω
c. 2.8 Ω
d. 4.2 mΩ
e. 700 mΩ
f. 1.3 Ω
4.
(1) Approximately (within 10%) what is the cold static resistance?
a. 48 Ω
b. 26 Ω
c. 2.8 Ω
d. 4.2 mΩ
e. 700 mΩ
f. 1.3 Ω