Electrical Engineering Glossary

A graphical representation of a system's frequency response using two plots: magnitude (in dB) and phase (in degrees) versus frequency on a logarithmic scale.

The ability of a component to store electric charge, measured in farads (F). A capacitor with higher capacitance stores more charge at a given voltage ($Q = CV$).

The rate of flow of electric charge past a point in a circuit, measured in amperes (A). Conventional current flows from positive to negative, while electron flow is in the opposite direction.

A logarithmic unit used to express the ratio of two values, commonly power or amplitude. In electronics, it quantifies gain, attenuation, and signal-to-noise ratios: $\text{dB} = 10 \cdot \log_{10}(P_2/P_1)$.

A two-terminal semiconductor device that allows current to flow primarily in one direction. It is based on a p-n junction and is used in rectification, voltage regulation, and signal demodulation.

The intentional introduction of impurity atoms into a semiconductor to modify its electrical properties. Adding donor atoms creates n-type material; adding acceptor atoms creates p-type material.

The routing of a portion of a system's output back to its input. Negative feedback stabilizes systems and reduces distortion; positive feedback can cause oscillation or bistable behavior.

A circuit that selectively passes or blocks certain frequency ranges from a signal. Types include low-pass, high-pass, band-pass, and band-stop (notch) filters.

A mathematical operation that decomposes a time-domain signal into its constituent frequency components, revealing the signal's spectral content.

A characterization of how a system responds to different input frequencies, typically plotted as gain and phase versus frequency on a Bode plot.

The practice of connecting a circuit or equipment to earth or a common reference point to ensure safety, reduce noise, and provide a stable voltage reference.

The property of a conductor by which a change in current induces an EMF in itself or a nearby conductor, measured in henrys (H). It opposes changes in current flow.

A mathematical technique that converts differential equations in the time domain to algebraic equations in the s-domain, simplifying the analysis of linear circuits and control systems.

A compact integrated circuit containing a processor, memory, and programmable I/O peripherals on a single chip. Used extensively in embedded systems, from appliances to automotive controls.

Metal-Oxide-Semiconductor Field-Effect Transistor, the most widely used transistor type in digital and analog circuits. Its gate voltage controls current between source and drain terminals.

A high-gain voltage amplifier with differential inputs and a single output. With feedback, it performs precise amplification, filtering, integration, and other signal processing functions.

The ratio of real power (watts) to apparent power (volt-amperes) in an AC circuit, ranging from 0 to 1. A power factor of 1 means all power delivered is consumed as useful work.

A modulation technique that varies the duty cycle of a digital signal to control the average power delivered to a load, commonly used for motor speed control and LED dimming.

The opposition to current flow from capacitors or inductors in an AC circuit, measured in ohms. Capacitive reactance decreases with frequency; inductive reactance increases with frequency.

A circuit that converts AC to DC using diodes. Common types include half-wave (one diode) and full-wave bridge (four diodes) rectifiers.

The opposition to the flow of electric current in a material, measured in ohms. It converts electrical energy into heat according to Joule's Law ($P = I^2R$).

A material with electrical conductivity between a conductor and an insulator, such as silicon or germanium. Its conductivity can be controlled by doping, temperature, or applied electric fields.

A device that transfers electrical energy between two or more circuits through electromagnetic induction, allowing voltage to be stepped up or down according to the turns ratio.

A semiconductor device used to amplify or switch electronic signals and power. The two main types are BJTs (current-controlled) and MOSFETs (voltage-controlled).

The electric potential difference between two points, measured in volts (V). It represents the energy per unit charge available to drive current through a circuit.