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

Options

A. decreases linearly with time
B. reaches a maximum and then decreases
C. falls to zero at time `t =a//2b`
D. changes at a rate - 2b

Answer

A, C, D

Explanation

`I=(dQ)/(dt) = a-2bt`
`I = 0for t = (a//b) and (dI)//dt) = -2b`