Self Inductance

Self Inductance Points : Self Inductance Imagine a coil of wire similar to the one connected to a battery through a rheostat. It is found that whenever an effort is made to increase current (and hence fl through it, it is always opposed by the instantaneous production of counter emf of self induction. Energy required to overcome this opposition is supplied by the battery. As will be fully explained later, this energy is stored in the additional flux produced.
If now an effort is made to decrease the current (and hence the flux), then again its is delayed due to the production of self induced emf, this time in the opposite direction. This property of the coil due to which it opposes any increase or decrease of current or flux through it, is known as self inductance. It is quantitatively measured in terms of coefficient of self inductance L. This property is analogous to inertia in a material body. We know by experience that initially it is difficult to set a heavy body into motion, but one in motion, it is equally difficult to stop It. Similarly, in a coil having large self induction, it is initially difficult to establish a current through it, but once established, it is equally difficult to withdraw it. Hence, self induction analogously called electrical inertia or electromagnetic inertia.