300 A . s or 300C. The amount of electric charge that flows through an electric bulb that drain a current of 0.25 for 20 minutes is 300 A . s = 300C.
Current is the amount of charge moving through a cross-sectional area of a conductor per second, and the unit for current is the coulomb/second, or ampere. It is define by the equation I = Δq/Δt.
Let's clear Δq from I = Δq/Δt:
20 minutes contains 1200 seconds
Δq = I Δt = (0.25A)(1200s) =
Δq = 300 A . s or 300C.