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.

I. The region of negative part is DE, because the slope is negative for this part of curve.

II. BC obeys ohm’s law, because there is variation in current (I) and voltage (V). This gives direct proportionality between current and voltage.