Question

In a few sentences explain how you can perform and experiment to find out if a circuit element is ohmic or nonohmic. What measurements do you make and how do you decide, based on the results of your measurements.

Answer 1

To perform an experiment to find out weather my circuit element is ohmic or non ohmic we have to follow the following steps :-

1. We have to take two seperate circuit both consisting of A variable voltage source, A voltmeter, an ammeter and an element ( initially not identified weather ohmic or not)

2. Now connect the variable voltage source ammeter and our testing element in series with each other and voltmeter in parallel to the testing element for both the circuit.

3. Now using variable source supply the voltage in both the circuit.

4. Measure the current in the circuit and voltage across the circuit and record it on a table.

5. Plot the graph between voltage applied across the testing element on the y axis and the current through it on x axis with atleast 5 or 6 intervals.

6.Now try to find weather the graph between the voltage and circuit is linear or non linear.

Result -: If the graph between voltage and current for the circuit gives linear graph and its slope is gives the value of resistance then we can say that here

V is directly proportional to the current and hence it follows ohms law so that it is an ohmic element

But if it is found that current is not linearly vary with voltage then it is non ohmic element.