The discussion centers on the omission of the minus sign in the voltage across an inductor, despite Faraday's law stating emf = -d(flux)/dt. The voltage is often expressed as v = d(flux)/dt to simplify calculations, particularly when only the magnitude is needed. Lenz's law explains that the induced emf opposes the change that produces it, justifying the sign convention. When an inductor is in series with a battery and the switch is opened, the voltage across the inductor helps maintain current despite decreasing flux. Ultimately, Kirchhoff's law reinforces that the total voltage drops in a circuit must equal zero.
