Question

Graph showing the variation of current versus voltage for a material GaAs is shown in the figure. Identify the region of

(i) Negative resistance

(ii) Where Ohm's law is obeyed.

Answer 1

According to Ohm's Law, the current passing through a conductor is directly proportional to the voltage applied across it.

Thus $V\propto I$

$⟹\frac{V}{I}=R$

$R$ is the resistance of the conductor.

Hence for Ohm's law to obeyed, the slope of $I$ vs $V$ curve is constant and positive.

Hence region BC obeys Ohm's law.

For $R$ to be negative, slope of $I$ vs $V$ curve should be negative, which is there for region DE.