Final answer:
The voltage spike caused by opening a switch in a circuit with an inductor is explained by Faraday's Law of Induction, which indicates that a changing magnetic flux induces an electric current, and by Lenz's Law, stating that the induced current opposes the change causing it. Option A is correct.
Step-by-step explanation:
When a current is flowing in a circuit containing an inductor and the power switch is opened, the magnetic field surrounding the inductor collapses. This change in magnetic field induces a voltage in the inductor, which can result in a voltage spike.
This phenomenon is described by Faraday's Law of Induction, which states that a changing magnetic flux within an area enclosed by a conducting loop induces an electric current in the loop. Furthermore, Lenz's Law further clarifies that the direction of this induced current and the resultant emf (electromotive force) will oppose the change in magnetic flux that caused them.
This opposition is a result of the negative sign in the equation of Faraday's Law, which symbolizes the opposing nature of the induced emf as formulated by Heinrich Lenz.
In contrast, Ohm's Law deals with the relationship between voltage, current, and resistance in a conductor, which isn't directly linked to the effects of magnetic fields, and Ampère's Law relates to the magnetic field around a conductor carrying a steady electric current.