Clive W. Humphris

**INDUCTORS: Inductive Reactance. **

The opposition to current change in an inductor is called reactance and given the symbol XL (AC resistance) and expressed in Ohms. The back-EMF generated opposes the applied current change.

Whilst capacitors inhibit the flow of direct current and allow the passage of alternating currents, inductors exploit the opposite effect, they resist AC and allow DC to pass through. Therefore, inductors have a low reactance (AC resistance) at low frequencies which increases as the frequency is increased. Compare the graph waveforms for capacitive and inductive reactance, the Xc gives an exponential waveform and XL is a straight line.

You will see the effect of combining capacitive and inductive reactance when we look at tuned circuits.

Inductive reactance is proportional to the applied voltage frequency. Applying AC Ohm's Law using XL in place of R and will prove that as the frequency is increased so the current decreases.

- Table of Contents
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- Basic Electronics
- Conductor And Insulator
- Resistor Value Test
- Simple Dc Circuits
- Types Of Switching
- Variable Voltages
- Ohm's Law
- DC Voltage
- DC Current
- Series and Parallel Resistors
- AC Measurement
- AC Voltage and Current
- AC Theory
- RCL Series
- RCL Parallel
- Capacitance
- Capacitors
- Inductance
- Inductors
- Impedance
- Tuned Circuits
- Attenuators
- Passive Filters
- Active Filters
- Oscillators
- Circuit Theorems
- Complex Numbers
- DC Power
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- Silicon Controlled Rectifier
- Power Supply
- Voltage Regulation
- Magnetism
- Electrical Machines
- Transformers
- Three Phase Systems
- Energy Transfer and Cost
- Atomic Structures
- Diode Theory
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- Transistor Theory
- Bipolar Transistors
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- Active Transistor Circuits
- Field Effect Transistors
- Basic Operational Amplifier
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