Question

An inductance has a high resistance to $AC$ and low to $DC$. When a $DC$ voltage source having some $AC$ component superimposed on it sends current through an inductance to a load resistance:
A. the $DC$ voltage falls appreciably across the load and $AC$ component falls by only a small amount
B. the $AC$ voltage and $DC$ voltage falls by the same amount
C. both $AC$ and $DC$ voltage falls by the same small percentage
D. both $AC$ and $DC$ voltage falls to nearly zero

Answer 1

The tendency of an electrical conductor to resist a change in the electric current passing through it is known as inductance. A magnetic field is created around a conductor by the passage of electric current. The field strength is proportional to the current magnitude and follows any variations in current.

Complete step by step answer:
So far, we've looked at the behaviour of inductors linked to $DC$ sources, and ideally we now understand that when a $DC$ voltage is placed across an inductor, the increase of the current through it is dictated by the inductor's self-induced or back emf value, rather than being instantaneous.

Also, after five time constants, the inductor current continues to climb until it achieves its maximum steady state condition. The greatest current flowing through an inductive coil is limited solely by the resistive fraction of the coil's windings in Ohms, which is defined by the voltage-current ratio, $V/R$, as we know from Ohm's law. The flow of current through an inductor behaves substantially differently when an alternating or AC voltage is put across it than when a $DC$ voltage is supplied.

The phase mismatch between the voltage and current waveforms is caused by the action of a sinusoidal supply. In an $AC$ circuit, the resistance to current flow through the coils' windings is determined not only by the coil's inductance, but also by the frequency of the $AC$ waveform.

Hence option A is correct.

Note: The resistance to current passing through a coil in an $AC$ circuit is governed by the circuit's $AC$ resistance, often known as Impedance (Z). However, because resistance is usually linked with $DC$ circuits, the term reactance is commonly used to distinguish $DC$ resistance from $AC$ resistance.