What is the difference between a non inductive and inductive resistor?
Inductive Resistor: Any circuit in which a change in the current is accompanied by a change in the flow and thus the induced EMF is referred to as inductive. Therefore no EMF is induced in the coil and the coil has no inductance. A non-inductive resistor can be used to replace an inductive resistor. However, this may not be a realistic goal.
Normally, a resistor is wound in the form of a coil and therefore has a certain inductance. In electrical instruments, sometimes we need pure resistance or non-inductive resistance, because inductance introduces error.
By winding the resistance coil below, we can achieve non-inductive resistance.
I wind half of the number of turns in one direction, and then wind the remaining half of the number of turns in the opposite direction, following the same path. By doing so, the effective coil inductance becomes zero.
Why? Because, inductance is nothing more than the flow connection on the current unit.
Now, if a current passes through the coil above, the flow produced at half the number of rotations will cancel the flow produced by remaining half the number of rotations.
So there will be virtually no flow inside the coil and therefore the inductance will be zero. The coil will thus become a pure resistance or a non-inductive resistance.
Inductive Resistance: Any circuit in which a change in the current is accompanied by a change in the flow and thus the induced EMF is referred to as inductive.
The induction of a resistor is a very important point to consider when building a circuit, especially when dealing with switching or high frequency circuits. The structure of most resistors is very similar to that of an inductor.
They take a certain length of wire or film, depending on the resistance that they want to achieve, and wrap it around a core of ceramic, plastic, fiberglass, or some other non-conductive material.
Non-Inductive Resistance: If a double wire is wrapped around an insulating rod, the EMF cannot be induced because the wire is doubled back on itself in the middle and the double wire is wrapped around an insulator.
Thus, each turn of the coil has an adjacent turn that carries current in the opposite direction. The magnetic field generated by each other cancels each other.
Therefore, no EMF is induced in the coil and the coil has zero inductance. A non-inductive resistor can be used to replace an inductive resistor.
However, this may not be a realistic goal. Inductive resistors are generally cheaper to construct and are more often manufactured with higher nominal powers.