Final answer:
The question involves Physics and high school level electromagnetism, asking for the calculation of the emf induced in an inductor when the current is switched off. The formula to find the induced emf is emf = -L (dI/dt), and applying it to the given values results in an emf of 3.60 V.
Step-by-step explanation:
The student's question pertains to the concepts of electromagnetism within the subject of Physics, specifically regarding the behavior of inductors in electrical circuits. When a current changes in an inductor, it induces an electromotive force (emf) that opposes the change in current, according to Lenz's Law. This induced emf can be calculated using the formula emf = -L (dI/dt), where L is the inductance of the coil and (dI/dt) is the rate of change of current over time.
In the given scenario, for a 7.50 mH inductor with a 4.00 A current that is switched off in 8.33 ms, the induced emf opposing the change would be emf = -0.0075 H * (-4 A / 0.00833 s), resulting in an emf of 3.60 V. This calculation includes the minus sign from Lenz's law, which indicates that the direction of the induced emf opposes the change in current. However, the magnitude of the emf is what is typically reported.