Question

Graph showing the variation of current versus voltage for a material Ga As is shown in the figure, Identify the region of:
(i) negative resistance
(ii) where Ohm's law is obeyed

Answer 1

By Ohm's law, $V=IR$ or $I=V/R$

Thus, the resistance is inverse of slope of graph I vs V.

i) As the slope is negative for part DE so the resistance will be negative for part DE.

ii) According to Ohm's law, current $I$ is proportional to V so the part BC will obey Ohm's law.