The charge flowing in a conductor varies with times as `Q = at - bt^2.` Then, the current

Options

A. (i) , (ii)
B. (ii), (iii)
C. (i),(iii),(iv)
D. all

Answer

C

Explanation

`Q = a t - bt^(2)`
`I = (dQ)/(dt) = a-2bt`
`i=0 implies a = 2bt`
`i=0 implies a = 2bt = 0`
`t = qa/(2b)`
`(di)/(dt) = -2b`