Consider the above circuit. The N-channel MOSFET has been used as a low side switch to provide reverse polarity protection. A capacitor charges to the 12V supply(battery) voltage and subsequently the supply terminals are reversed. Since the capacitor will hold its charge for a certain period of time, it is therefore able to keep the MOSFET Vgs well above the minimum threshold voltage of 2.8V. As such on reversal, the capacitor discharges and settles its voltage to 2.8V after which the MOSFET turns off completely thereby disconnecting the circuit.
Well the above case seems to be impractical, but consider a situation where a startup delay of few seconds is given, the user might unknowingly reverse the polarity. As circuits contain innumerable capacitor and magnetic components that will be able to keep the mosfet on till their energy collapses in the biasing and other circuit loads, for that period the circuit seems to be in conduction mode even under reverse polarity.
Can anyone explain what will be the effect on vulnerable components that are a part of such a circuit? Also is there any way to mitigate this effect?