Question

(i) Draw a graph of V versus I for an ohmic resistor.

(ii) How can you find the resistance of the resistor from the graph.

(iii) What is a non-ohmic resistor?

Answer 1

(i) Drawing the graph between the V versus I for an ohmic resistor.

According to ohm's law

$V=RI$

Where,

$$\begin{gathered} V=Potentialdifference \\ I=Current \\ R=Resis\tan ce \end{gathered}$$

By comparing the equation$V=RI$ with $y=mx$ (where $m=$slope of the line) and passing origin.

We can draw the graph $V$ versus $I$

(ii) Finding the resistance from the $VversusI$ graph

The slope of $VversusI$ gives the resistance of the resistor.

So, we can find the slope of the $VversusI$ graph which is equal to the resistance of a resistor.

Now, from the above equation, we can say slope, $m=\tan \theta =R$.

(iii) Non-ohmic resistor:

Any resistor which does not follow the ohm's law is called a non-ohmic resistor.

Example: Semiconductor, Inductor, etc.