Chapter 13 – Electrical Systems (Vocabulary Review)

These vocabulary flashcards cover key terms and concepts from Chapter 13 on Electrical Systems, including basic circuit quantities, components, safety devices, effects of current, and energy conservation.

Electrical System

A collection of interconnected components (energy source, conducting wires, switch, load) that allows electric charge to flow and perform work.

Electric Circuit

A closed conducting path through which electric current can flow.

Electric Charge

A physical property of matter that causes it to experience a force when placed in an electromagnetic field; carried by electrons in circuits.

Electric Current (I)

The rate at which electric charge flows through a point in a circuit; measured in amperes (A).

Ammeter

Instrument connected in series to measure electric current flowing in a circuit.

Potential Difference (V)

Energy required to move one coulomb of charge between two points in a circuit; measured in volts (V).

Voltmeter

Instrument connected in parallel to measure potential difference across a component.

Electrical Resistance (R)

Opposition offered by a material or component to the flow of electric current; measured in ohms (Ω).

Conductor

Material with low resistance that allows current to flow easily, e.g., copper, silver.

Insulator

Material with very high resistance that prevents current flow, e.g., plastic, glass.

Resistor

Component designed to limit or control current in a circuit by providing resistance.

Series Circuit

Circuit configuration in which components are connected end-to-end so the same current flows through each component.

Parallel Circuit

Circuit configuration in which components are connected across common points, providing multiple current paths and equal potential difference across each branch.

Variable Resistor (Rheostat)

Adjustable resistor that varies circuit resistance to control current, e.g., dimmer switch.

Cell (Battery)

Electrochemical energy source that provides potential difference and drives current in a circuit.

Switch

Device that opens or closes an electrical circuit, controlling the flow of current.

Electromagnet

Temporary magnet produced when electric current flows through a coil of wire, often enhanced with an iron core.

Solenoid

Coil of wire that produces a magnetic field when current passes through it; basis of many electromagnets.

Chemical Effect of Current

Ability of an electric current to bring about chemical changes, as in electrolysis and electroplating.

Electrolysis

Process of using electrical energy to decompose a compound into its elements, e.g., extracting aluminium from bauxite.

Electroplating

Coating an object with a thin layer of metal by passing current through an electrolyte containing the desired metal ions.

Heating Effect of Current

Conversion of electrical energy to thermal energy when current passes through a resistance, used in heaters and incubators.

Magnetic Effect of Current

Creation of a magnetic field around a conductor when current flows, forming the basis of motors and MRI scanners.

Fuse

Safety device containing a thin wire that melts (blows) to break a circuit when current exceeds a specified rating.

Circuit Breaker

Resettable protective switch that automatically opens a circuit when excessive current is detected.

Residual Current Circuit Breaker (RCCB)

Circuit breaker that disconnects supply when it detects a difference between live and neutral currents, preventing electric shock.

Electrical Power (P)

Rate at which electrical energy is converted to other forms; measured in watts (W).

Watt (W)

SI unit of power; equivalent to one joule of energy converted per second.

Kilowatt-hour (kWh)

Unit of electrical energy equal to using 1 kilowatt of power for 1 hour; common billing unit for household electricity.

Energy Efficiency Label

Mandatory label (Singapore) rating appliances from 1–5 ticks to indicate relative energy consumption and annual cost.

Electricity Tariff

Cost per unit of electrical energy (¢/kWh) set by the Energy Market Authority and revised quarterly.

Overloading

Drawing too much current from a single socket or circuit, which can overheat wires and cause fires.

Short Circuit

Accidental low-resistance connection that allows excessive current to bypass the intended load, posing fire and shock hazards.

Electrical Hazard

Potential danger from electric shock, electrocution, or fire resulting from improper use or faults in electrical systems.

Energy Conservation (Household)

Practices and choices (e.g., using LED bulbs, switching off unused appliances) that reduce electrical energy consumption and costs.