The newtwork shown is a part of the closed circuit in which the current is changing. At an instant, current in it is `5A`. Potential difference between the points `A` and `B` if the current is

(1) Increasing at `1A//sec`
(2) Decreasing at `1A//sec`

Explanation

`{:1)` The coil can be imagined as a cell of emf
`e = L((di)/(dt)) = 5 xx 1 = 5V`, `:.` Equivalent circuit is

`V_(A) - 5(1)-15-5 = V_(B)`
Hence `V_(A) - V_(B) = 5+15+5 = 25V`
`{:2)` The coil can be imagined as a cell of emf
`e = L((d i)/(dt)) = 5 xx 1 = 5V`, `:.` Equivalent circuit is

`V_(A) = 5(1)-15+5 = V_(B)`
Hence `V_(A)-V_(B) = 5+15-5 = 15V`