Tools

Ohms Law            

Procedure

Experiment

Let us go through the experiment of confirming Ohms Law.

  1. Set DC voltage(0-30 V).
  2. Set the Resistance Value(1 Kohm - 100 Kohm) .
  3. Voltmeter is placed parallel to resistor and ammeter series with resistor.
  4. Now note the Voltmeter and Ammeter reading for DC voltage.
  5. Increase the DC voltage by 2 factor and note Voltmeter and Ammeter Readings. Keep resistance value constant
  6. Plot the V-I graph to verify Ohm's Law.
  7. Repeat step 2 to 6 for another set of resistance value.
  8. V versus I graph is a straight line.
  9. Therefore from the graph we see that the resistance do adhere to Ohm’s law. Thus resistance is said to be an Ohmic device.

Figure:1

Let us go through the experiment of confirming Ohms Law with Resistance in series.

  1. Set DC voltage(0-30 V).
  2. Here resistance are kept in series. Set the resistance R1(1 Kohm - 100 Kohm) value and set resistance R2(5 - 15 Kohm).
  3. Voltmeter is placed parallel with resistor and ammeter series with resistor.
  4. Now note the Voltmeter and Ammeter reading for DC voltage.
  5. Increase the DC voltage by 2 factor and note Voltmeter and Ammeter Readings. Keeping resistance value constant
  6. Plot the V-I graph to verify Ohm's Law
  7. Repeat step 2 to 6 for another set of resistance value.

Figure: 2

Let us go through the experiment of confirming Ohms Law with Resistance in parallel.

  • Set DC voltage(0-30 V).
  • Here Resistances are kept parallelly. Set the resistance R1 (100 ohm- 2 kohm) value and set resistance R2(1 -30 kohm).
  • Voltmeter is placed parallel to resistor and ammeter series with resistor.
  • Now note the Voltmeter and Ammeter reading for DC voltage.
  • Increase the DC voltage by 2 factor and note Voltmeter and Ammeter Readings. Keeping Resistance value constant
  • Plot the V-I graph to verify Ohm's Law.
  • Repeat step 2 to 6 for another set of resistance value.

Figure: 3

Exploratory Experiment

Let us go through the experiment of confirming Non Ohmic Device.

  • Set DC voltage to 5 V .
  • Use the resistor of 100K ohms and a diode.
  • Voltmeter is placed parallel to Silicon diode and ammeter series with resistor.
  • Now note the Voltmeter and Ammeter reading for DC voltage 5V.
  • Decrease the Resistance as 75K, 51K, 24K and 10K Ohms and take the readings and note Voltmeter reading across Silicon diode and Ammeter reading.
  • Plot the V-I graph and observe the change.
  • The Change is not simply proportional. V versus I graph is not a straight line.
  • Therefore from the graph we see that the diode does not adhere to Ohms law.Thus diode is said to be non-Ohmic device.

Figure: 4