Experiment # P206 General College Physics I
Dr. S.F. Ahmad
DC Series Resistor Circuit
Name:
Group Names:
Object: To study voltage and current relationships in a direct
current series resistor circuit. Verify
Ohm’s Law.
Apparatus: Multimeter, resistors, power supply and connecting wires.
Theory: Detailed theory about resistors has been discussed in
class.
Series resistors add up as RT = R1 + R2
+ R3
And
Ohm’s Law V = I R is used to calculate the voltage across each
resistor or to find the current through each resistor. Power used is given by P = V I = V2R = I2R.
Observations: Use the
following circuit for the experiment:
TABLE I:
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VR1 |
VR2 |
VR3 |
Current in
the circuit |
Power given
by the battery |
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Procedure:
1. Wire the circuit as shown.
2. Do not turn on power unless the instructor has inspected
your circuit.
3. Turn the power on once the inspection is done.
4. Use
the digital multimeter in the DC voltmeter setting and select range of 20 to 30
volts.
5. Measure
the power supply voltage and set it to 2.0 V.
6. Measure
the voltage across each resistor and record your observations in Table 1.
7. Change
power supply voltages to 5V, 8V, 10V, 12V and 15V and repeat step 6.
8. Ask
the instructor to help you build the circuit for measuring the current.
9. Complete the table with your calculations indicated.
10. Draw a
graph of V on the x-axis and I on the y-axis for each resistor. This should come out to be a straight line
for each resistor. Calculate the slope
of each line and find the resistance value (slope = 1/R) from the graph. Compare it with the known value of each
resistor.
Sample Calculations:
RESULTS: Report
your results in a brief statement.
Sources of Error:
Calculate
percentage error in your results if you know accurate values.
Write
down the sources of error in this experiment.