Procedure: Ohm's Law Experiment

Experiment 1: Confirming Ohm's Law

Follow these steps to confirm Ohm's Law:

  1. Set the DC voltage between 0-30 V.
  2. Set the resistance value between 1kΩ and 100kΩ.
  3. Place the voltmeter in parallel with the resistor and the ammeter in series with the resistor.
  4. Note the readings of the voltmeter and ammeter for the DC voltage.
  5. Increase the DC voltage by a factor of 2 and note the voltmeter and ammeter readings. Keep the resistance value constant.
  6. Plot the V-I graph to verify Ohm's Law.
  7. Repeat steps 2 to 6 for another set of resistance values.

The V-I graph should be a straight line, confirming that the resistance adheres to Ohm’s Law, thus proving the resistor is an Ohmic device.

Ohm's Law Experiment
Figure 1: Ohm's Law Experiment Setup

Experiment 2: Confirming Ohm's Law with Resistance in Series

Follow these steps to confirm Ohm's Law with resistors in series:

  1. Set the DC voltage between 0-30 V.
  2. Set resistance values for R1 between 1kΩ and 100kΩ and R2 between 5kΩ and 15kΩ in series.
  3. Place the voltmeter in parallel with the resistor and the ammeter in series with the resistor.
  4. Note the readings of the voltmeter and ammeter for the DC voltage.
  5. Increase the DC voltage by a factor of 2 and note the readings of the voltmeter and ammeter. Keep the resistance values constant.
  6. Plot the V-I graph to verify Ohm's Law.
  7. Repeat steps 2 to 6 for another set of resistance values.

The V-I graph should be a straight line, confirming that the series circuit follows Ohm's Law.

Resistance in Series Experiment
Figure 2: Resistance in Series Experiment Setup

Experiment 3: Confirming Ohm's Law with Resistance in Parallel

Follow these steps to confirm Ohm's Law with resistors in parallel:

  1. Set the DC voltage between 0-30 V.
  2. Set resistance values for R1 between 100Ω and 2kΩ, and R2 between 1kΩ and 30kΩ in parallel.
  3. Place the voltmeter in parallel with the resistors and the ammeter in series with the resistors.
  4. Note the readings of the voltmeter and ammeter for the DC voltage.
  5. Increase the DC voltage by a factor of 2 and note the voltmeter and ammeter readings. Keep the resistance values constant.
  6. Plot the V-I graph to verify Ohm's Law.
  7. Repeat steps 2 to 6 for another set of resistance values.

The V-I graph should be a straight line, confirming that the parallel circuit follows Ohm's Law.

Resistance in Parallel Experiment
Figure 3: Resistance in Parallel Experiment Setup

Exploratory Experiment: Confirming Non-Ohmic Devices

To confirm the behavior of a Non-Ohmic device, follow these steps:

  1. Set the DC voltage to 5V.
  2. Use a 100kΩ resistor and a diode in the circuit.
  3. Place the voltmeter in parallel with the silicon diode and the ammeter in series with the resistor.
  4. Note the readings of the voltmeter and ammeter for the 5V DC voltage.
  5. Decrease the resistance to 75kΩ, 51kΩ, 24kΩ, and 10kΩ in steps, and record the voltmeter and ammeter readings for each resistance value.
  6. Plot the V-I graph and observe the changes.

The V-I graph will not be a straight line, showing that the diode does not obey Ohm's Law. Therefore, the diode is a Non-Ohmic device.

Non-Ohmic Device Experiment
Figure 4: Non-Ohmic Device Experiment Setup