Electrical Engineering Review Flashcards (Booklet 46/24 Alpha Code A)

Vocabulary practice flashcards covering electrical fundamentals, machines, wiring codes, instrumentation, and power systems based on Question Booklet 46/24 Code A.

Electric Charge

A fundamental physical quantity where total charge equals current multiplied by time ($Q = I \times t$), with a single electron possessing a charge of $1.602 \times 10^{-19}\,\text{C}$.

Solder Alloy

A fusible metal alloy whose main constituent elements are tin and lead, with silver-based variants utilized for high-temperature soldering applications.

Soldering Flux

A chemical cleaning agent used in soldering that removes the surface oxide layer from metals, though it cannot remove dirt or grease.

Volt

The SI unit of electrical potential difference, equivalent to Weber per second ($\text{Wb/s}$).

Dielectric Strength

A key desirable property of an insulating material indicating its ability to withstand high electric fields without undergoing breakdown.

Semiconductor

A material (such as silicon, germanium, or carbon) having 4 valence electrons and characteristically displaying a negative temperature coefficient of resistance.

Resistivity

An intrinsic physical property of a conductor that determines its electrical resistance and does not depend on the physical dimensions or size of the conductor.

Kirchhoff's Current Law (KCL)

A circuit analysis principle stating that the algebraic sum of currents entering and leaving any electrical junction or node is zero.

Kirchhoff's Voltage Law (KVL)

A circuit analysis principle stating that the directed sum of potential differences around any closed loop in a circuit equals zero.

Electroplating

An industrial coating process that utilizes the chemical effect of electric current to deposit a layer of metal onto a surface.

Ohm's Law

A law stating current is directly proportional to voltage at constant temperature; it applies to linear conductors but fails for non-linear components such as Zener diodes.

Constantan

A specialized alloy that exhibits virtually zero change in electrical resistance over a broad variation in temperature.

Primary Cell

An electrochemical cell (such as a Voltaic cell or Carbon-Zinc cell with ammonium chloride electrolyte) that generates electricity via irreversible chemical reactions and cannot be recharged.

Secondary Cell

An electrochemical cell (such as a lead-acid battery using sulphuric acid electrolyte) capable of being recharged by passing electrical current in reverse.

Ferromagnetic Material

A class of magnetic substances (such as iron) that are strongly attracted by a magnetic field.

Paramagnetic Material

A class of magnetic substances (such as aluminium) that are weakly attracted by a magnetic field.

Diamagnetic Material

A class of magnetic substances (such as bismuth) that are weakly repelled by a magnetic field.

Tesla

The standard SI unit of magnetic flux density, defined as one Weber per square metre ($1\,\text{T} = 1\,\text{Wb/m}^2$).

Fleming's Right-Hand Rule

A rule used to determine the direction of induced EMF in a conductor moving through a magnetic field, applied in DC generators.

Fleming's Left-Hand Rule

A rule used to find the direction of force exerted on a current-carrying conductor placed within a magnetic field, applied in electric motors.

Permeance

The property of a magnetic circuit that measures the ease with which magnetic flux is established, defined as the reciprocal of reluctance.

Megger

A specialized measuring instrument used to evaluate the high insulation resistance of electrical wiring installations.

Fall of Potential Method

The fundamental measurement technique and working principle employed by an earth resistance tester.

Goliath Edison Screw Type Holder

A heavy-duty lamp holder designed for high-wattage lamps exceeding $300\,\text{W}$, commonly used in studios, floodlights, and headlights.

MCCB (Molded Case Circuit Breaker)

A protective circuit breaker typically employed for current ratings ranging above $100\,\text{A}$ up to $800\,\text{A}$.

Faraday's Laws of Electromagnetic Induction

The core principle stating that an EMF is induced in a conductor when relative motion or flux linkage variation exists between the conductor and a magnetic field.

Armature Lamination

The process of assembling the armature core from thin insulated steel sheets to minimize eddy current losses.

Ward Leonard Speed Control

A DC motor speed control method capable of providing smooth and wide speed variation both below and above normal rated speed.

Squirrel Cage Rotor

An induction motor rotor structure comprising conductive rotor bars permanently short-circuited at both ends by heavy end rings.

Grommet

An insulating panel accessory inserted into drilled holes to hold and protect electrical cables from sharp metal edges.

Ferrule

A marked sleeve or band attached to wires and cables in electrical panel boards for clear circuit identification.

Damping Torque

The torque produced in an indicating instrument to quickly bring the moving pointer to rest at its final position without excessive oscillation.

Mutual Induction

The working principle of a two-winding transformer, where varying current in the primary winding induces a proportional EMF in the secondary winding.

Lumens per Watt

The standard SI unit used to quantify lamp efficiency or luminous efficacy.

Fluorescent Choke

An inductive ballast in a fluorescent lamp circuit that produces a high-voltage surge for arc ignition and limits running current during operation.

Knee Voltage

The forward bias voltage threshold at which a semiconductor diode begins conducting heavily, equal to $0.7\,\text{V}$ for a silicon diode.

Ripple Factor

A ratio indicating the effectiveness of AC-to-DC rectification, measuring $0.482$ for a single-phase full-wave bridge rectifier.

Economizer

A heat-recovery accessory in a thermal power plant that uses residual heat from exit flue gases to preheat boiler feed water.

Surge Tank

A water reservoir built into penstock lines of hydroelectric plants to absorb excess pressure and relieve water hammer phenomena.

Hydrograph

A graphical plot representing water discharge against time for a specific watercourse or hydel plant source.

Pelton Wheel

An impulse-type hydraulic turbine specifically suited for high-head, low-discharge hydroelectric installations.

Back-to-Back DC Link

A high-voltage DC system used to interconnect two adjacent AC power networks operating at different frequencies or un-synchronized phases.