An alternating current `I` in an inductance coil varies with time `t` according to the graph as shown: Which one of the following graph gives the variation of voltage with time?

Options

A.
B.
C.
D.

Answer

D

Explanation

As is clear from fig.
current increases uniformaly form t = 0 to `t = T//2` and decreases uniformaly at the same rate from
`t = T//2` to `t =T`
`:. (dI)/(dt) ` is positive constant in the first half
`(0 rarr T//2)` and `(dI)/(dt)` is negative constant of same value in the second half `(T//2 rarr T)`.
As `V = L (dI)/(dt) =` positive constant from t = 0 to
`t = T//2` and `V = L (dI)/(dt)` = negative constant form
`t = T//2` to t = T
choice (d) is correcte in Fig.