Chapter 10 Inductors, RL Circuits, Diodes, and BJT Fundamentals

What is an inductor?

A passive electrical component that stores energy in a magnetic field when an electric current passes through it.

What are air core inductors used for?

They are suitable for limited space, high linearity, high frequency, and reduced core loss.

What is the main characteristic of iron core inductors?

They have high magnetic permeability, leading to higher inductance.

What is a toroidal inductor?

An inductor with a donut-shaped core made of powdered iron or ferrite, providing high inductance for its size.

What is the formula for inductance (L)?

L = (μN²A) / l, where μ is permeability, N is the number of turns, A is the area, and l is the length of the coil.

What does magnetic permeability indicate?

It indicates how easily a material can support the formation of a magnetic field within itself.

What is an RL circuit?

A circuit composed of a resistor and an inductor, driven by a current or voltage source.

What is the power factor in an RL circuit?

The ratio of the actual power dissipated to the apparent power, represented as cos ϕ.

What is the time constant (τ) of an RL circuit?

τ = L / R, where L is inductance in henries and R is resistance in ohms.

What is a diode?

A semiconductor device that primarily allows current to flow in one direction.

What is the construction of a P-N junction diode?

Formed by joining a P-type semiconductor and an N-type semiconductor.

What is the function of a Schottky diode?

It allows current flow with a very low forward voltage drop and fast switching speed.

What is the main application of a Zener diode?

Used in reverse bias configuration to provide a stabilized voltage and protect circuits from overvoltage.

What is a bipolar junction transistor (BJT)?

A semiconductor device that uses both electrons and holes as charge carriers.

What are the functions of a BJT?

Amplification, switching, filtering, rectifying, and oscillating.

What is current gain in a BJT?

The ratio of the collector current (IC) to the base current (IB), represented by β or hFE.

What does the term 'forward bias' mean in diodes?

It refers to the condition where current flows from the anode to the cathode.

What is the significance of the Zener voltage?

It is the reverse voltage at which a Zener diode allows current to flow.

What is the difference between a standard diode and a Zener diode?

A Zener diode allows current to flow in both directions under specific conditions, while a standard diode only allows forward current.

What is the role of inductors in filtering circuits?

Inductors help to smooth out fluctuations in current and voltage, providing stable outputs.

How does a light-emitting diode (LED) work?

It emits light when forward-biased as charge carriers recombine across the junction, releasing photons.