(c) If the permeability is large, s

(c) If the permeability is large, so is the inductance of the coil. Therefore, the emf is also very large. If permeability tends to
infinity, so does the induced emf. The same effect can be obtained with finite permeability by increasing the magnitude
of the time derivative of the current (in this case, by increasing the frequency). This effect is responsible for large pulses
that occur when the current in inductive circuits is changed quickly (such as when connecting or disconnecting a circuit).
In electronic circuits, it is often required to protect devices, such as output power stages in amplifiers, motor and relay
drivers, and the like, from being damaged due to inductive pulses.