Question

From the graph between current I and voltage V shown below, identify the portion corresponding to negative resistance

Answer 1

First, look at the graph closely.

The gradient rises at point B, falls with C, experiences the lowest point at D, and that is from where to again ascends towards point E.

We know that,

Negative resistance = – (V/I) = [V/(– I)]

In this case, the portion of the gradient which corresponds to negative resistance is CD.

Ans) CD is the portion of the slope or gradient where the resistance is negative

Answer 2

Given:

The graph between current I and voltage V.

To find:

Identify the portion corresponding to negative resistance

Solution:

From the graph, it's clear that,  

The gradient falls from point C till point D.

we know that,

V = IR

R = V/I

with the increase in current the voltage decreases gradually in the portion of the CD.

So, we have,

R = (-V)/(+I)

R = - V/I

The negative sign indicates the negative resistance.

Therefore, the CD is the portion corresponding to negative resistance.