Is the graph showing variation of current versus voltage for a diode linear or non-linear?

Plot a graph showing variation of current versus voltage for the material Ga.

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

Draw the graph showing the variation of current with voltage for a p-n junctin diode when the diode is (i) forward biased and (ii) reyerse biased

(a) Draw graph showing the variation of current versus voltage in an electroyte when an external resistance is also connceted. (b) (i) The graph between resistance (R ) and temperature (T) for Hg is shown in the figure (a). Explain the behaviour of Hg near 4k. (ii) In which region of the graph shown in the figure (b) is the resistance negative and why?