Hi, I can't figure out what is the physical reason behind the fact that, in DC RL circuit, for example, the series one, the current rises from zero (supposing state zero response), to its maximum value given by ohm's law. I've understood it mathematically but I can't physically explain why, after the current being zero at the very zero instant of time, it starts increasing over time. For current to flow voltage across L must be less than the EMF of the DC power supply but this implies that over time voltage across L, which is back EMF with a minus sign, decreases over time. Again I can't find a physical reason to this fact that voltage across L decreases over time. Thanks in advance to anyone who tries to make me understand this.