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 Main Online Paper (Held On 10 April 2015)

A)

B)                

C)

D)

Correct Answer: A

Solution :

                 \[{{V}_{d}}\propto \sqrt{E}\]     \[I=neA{{V}_{d}}\] and \[E=\frac{V}{l}\]so \[E\propto V\]and \[I\propto {{V}_{d}}\] so \[I\propto \sqrt{V}\]\[{{I}^{2}}\propto V\]