question_answer

Suppose the drift velocity Vi in a material varied with the applied electric field E as \[{{\upsilon }_{d}}\propto \sqrt{E}.\]Then V - I graph for a wire made of such a material is best given by:                                                      [JEE ONLINE 10-04-2015]

A)           

B)

C)

D)

Correct Answer: A

Solution :

[a] \[{{V}_{d}}\propto \sqrt{E}\]            \[I=neA{{V}_{d}}\]

and \[E=\frac{V}{l}\]so \[E\propto V\]and \[I\propto {{V}_{d}}\]

so \[I\propto \sqrt{V}\]                \[{{I}^{2}}\propto V\]