What is Inductor | Inductor in DC and AC circuits

Inductor is an coil. In  which a long conductor  is wound with number of circular turns of wire (like copper and aluminium ) to close together to form a coil.so it is also called coil. The long conductor core may be made of steel , iron and some other material. the part in which wire is wound is called core of conductor.these turns of wire is insulated to each other.it has two leads.one is staring turn of coil and other is finishing turn coil. The connecting these leads  by supply coil is excited. 

Inductor is a one passive two terminal electrical  component of three passive  electrical component Resistor, Inductor and Capacitor.which is store the electrical energy as a magnetic field which produce by coil. which show the electromagnetic relation. Inductor is characterized by its inductance. It is the property of inductor.

When the current flowing through an inductor. it property inductance oppose sudden any changes of current. otherwise it can say that chock the current so it is also called chock. Direction of current and magnetic field are calculated by right hand rule.

A current carries conductor generates the magnetic field surrounding it.the magnetic flux is generated by current. any changing in the current flowing in inductor magnetic field induces a voltage in the conductor, described by  Faraday's law of induction. According to Lenz's law, the direction of induced  Voltage (e.m.f.) defined.

In the International system of units the unit of inductane is henry (H). Inductors have values that typically rne from 1 µH (10⁻⁶H) to 20 H.It is denated by L.

There are many type of inductor

• Air Core Inductor.
• Inductor with iron core    
• inductor with ferrite core.
• Iron Powder Cores.
• laminated-core-inductor.
• Two Bobbin Inductor.
• Toroidal Inductor.
• Multi-layer Ceramic Inductors

Symbols

Inductance
The Property of a Inductor Or Coil due to which is opposes the changing of current flowing through itself is called inductance. So  Inductance is the property of Inductor Or Coil.

Due to this property of inductor produces voltage in the inductor itself by the changing current flowing through it.So induce voltage(emf) across coil is proportional to the rate of change of current. this Relation given blow.

Here L Is the proportional constant of this relation. it is called Inductance of coil.  this change of field induces a voltage V (emf) across the coil, given by  ( Lenz's law ) 

It may be noted here that the voltage across the inductor would be zero if the 

current though it remains constant.

Inductor in dc circuits

When an Inductor is connected to a circuit with Direct Current (DC) source, two processes , which are called "storing" and "decaying" energy, will happen in 

specific conditions. 

The Inductor is connected to the DC Power Supply. The sudden increase of  current in the Inductor produces an Self Induced Electromotive Force v_emf opposing the Current change. This appears as a Voltage across the Inductor, VL=- v_emf. This - v_emf will slow down the Current change, and in turn,the slow own of the Current change, will make VL become smaller. When the Current becomes stable, the Inductor creates no more opposition and VL becomes zero,  the Storage Phase is over.

• In inductor in dc circuit At start initial condition behaves open circuit.
• Inductor in steady state condition behaves short circuits.
• Voltage across the inductor in steady state is zero.and  steady state condition behaves short circuits.

Power absorbed by inductor in dc circuit is given the relation.

Inductor in ac circuits

In Ac Circuits. An Inductor is connected with AC source in series having negligible resistance. when a sinusoidal voltage is applied to an Indutor.  the voltage leads the current by one-fourth of a cycle, or by a 90º phase angle.that means current lags behind the voltage by  90º phase angle. show the waveform of in which current in 90º is zero and voltage across inductor is negative maximum magnitude, when current is start increasing then voltage is start decreasing in negative half cycle. when current reach maximum magnitude and induce (emg) voltage is zero.

  1. An Inductor  the voltage leads the current by one-fourth of a cycle, or by            a 90º phase angle.
  2. The rms value of current through an inductor is given by a relation of                ohm'law I_{rms =}  V_rms / XL . XL is the inductive reactance of inductor. 
  3. Inductor In positive half cycle store the power and negative half cycle                release  the power.

  4. The current lags the voltage by 90º phase angle.

The Average Power Consumed in a pure inductor is zero.