Maharashtra SSC Electronics Technology Pre-Voc/NSQF key terms

The electrical potential difference between two points, measured in volts (V). It represents the energy per unit charge that drives current through a circuit.

The rate of flow of electric charge through a conductor, measured in amperes (A). One ampere equals one coulomb of charge passing a point per second.

The opposition to the flow of electric current in a material, measured in ohms (Ω). It converts electrical energy into heat and limits current in a circuit.

A fundamental relationship stating that current through a conductor is directly proportional to voltage and inversely proportional to resistance: V = I × R. It is used to calculate any one quantity when the other two are known.

A passive electronic component with a specific resistance value, used to limit current, divide voltage, or bias active devices. Its value is marked by a colour code or printed digits.

A passive component that stores electrical energy in an electric field between two conductive plates separated by a dielectric. It is measured in farads (F) and blocks direct current while passing alternating current.

A two-terminal semiconductor device that allows current to flow easily in one direction (forward bias) and blocks it in the opposite direction (reverse bias). It is used for rectification and protection.

A light-emitting diode: a semiconductor diode that emits light when forward-biased. It is energy-efficient, has a long life, and is used as an indicator or in lighting, always with a series current-limiting resistor.

A three-terminal semiconductor device (bipolar junction or field-effect) used to amplify signals or switch currents. A small base or gate signal controls a larger current between collector and emitter (or drain and source).

A standard system of coloured bands on resistors and some capacitors that indicates their value and tolerance. Each colour represents a digit or multiplier; for example, brown-black-red means 1 kΩ.

A circuit that converts alternating current (AC) into direct current (DC) using diodes. A half-wave rectifier uses one diode; a full-wave bridge uses four diodes for better efficiency.

A test instrument that measures voltage, current, resistance, and often continuity or diode drop. It is connected in parallel for voltage and in series for current; the correct function and range must be selected before use.

An instrument that displays a voltage waveform on a screen as a graph of voltage against time. It is used to observe signal shape, amplitude, frequency, and timing in electronic circuits.

A process of joining metal parts by melting a filler alloy (solder) that wets the surfaces and solidifies to form an electrical and mechanical bond. In electronics, rosin flux and a soldering iron are used.

A chemical agent applied during soldering to remove oxide films from metal surfaces and help molten solder wet and bond properly. Rosin flux is common; it should be cleaned after soldering to prevent corrosion.

A soldered connection that looks dull, grainy, or blobby because the solder did not properly wet the surfaces. It has high resistance and can cause intermittent faults; it is repaired by re-soldering with fresh flux.

Printed circuit board: an insulating board (usually fibreglass) with copper tracks that connect components. It provides mechanical support and replaces most point-to-point wiring in electronic products.

A PCB assembly method in which component leads pass through holes in the board and are soldered on the opposite side. It gives strong mechanical joints but uses more board area than surface-mount technology.

Surface-mount device: a component designed to be soldered directly onto the surface of a PCB without through-holes. SMD parts are small, allow dense boards, and require fine soldering or reflow techniques.

A digital circuit that performs a basic Boolean operation such as AND, OR, NOT, NAND, NOR, or XOR. Its output depends on the combination of binary inputs, forming the building blocks of digital systems.

A table listing all possible input combinations of a logic circuit and the corresponding output for each. It is used to analyse, design, and verify digital logic functions.

A number system using only two digits, 0 and 1, which correspond to the low and high logic levels in digital electronics. Each binary digit is called a bit; eight bits form a byte.

A digital memory circuit that stores one bit and has two stable states. It changes state only when clocked or triggered, making it the basis of registers, counters, and memory in digital systems.

A circuit or unit that provides the required DC voltages to electronic equipment from a mains AC or battery source. It typically includes a transformer, rectifier, filter, and regulator stages.

A circuit, usually a capacitor (often with a resistor or inductor), that smooths the pulsating DC output of a rectifier into a steadier DC voltage by reducing ripple.

A device or circuit that holds the output voltage of a power supply constant despite changes in input voltage or load current. Common types include the 78xx series fixed regulators and adjustable regulators.

A device that converts stored chemical energy into electrical energy, providing DC power. It has a rated voltage and capacity in ampere-hours; primary cells are not rechargeable, while secondary cells are.

A single integrated circuit containing a processor, memory, and input/output peripherals, programmed to control devices and processes. Examples include the 8051 and Arduino-compatible chips.

A device that detects a physical quantity such as temperature, light, or motion and converts it into an electrical signal. Sensors provide input data to microcontrollers and control systems.

General-purpose input/output: a programmable digital pin on a microcontroller that can be configured as an input (to read a sensor) or an output (to drive an LED or relay).

A dedicated computer system built into a larger device to perform a specific control task, often using a microcontroller. Examples include washing machines, digital watches, and automotive controllers.

Connecting exposed metal parts of electrical equipment to the earth through a low-resistance path so that fault currents flow safely to ground, protecting users from electric shock.

A protective device containing a metal wire or strip that melts and breaks the circuit when the current exceeds its rating, preventing overheating and fire. It must be replaced after operation.

Miniature circuit breaker: an automatically operated switch that trips and opens the circuit on overload or short circuit. Unlike a fuse, it can be reset and reused after the fault is cleared.

The passage of electric current through the human body, which can cause burns, muscle contraction, and heart failure. Prevention includes insulation, earthing, and avoiding contact with live conductors.

Electrostatic discharge: a sudden transfer of static charge between objects, which can damage sensitive electronic components such as ICs and MOSFETs. Prevention includes wrist straps, mats, and anti-static packaging.

The process of identifying an opportunity, organising resources, and taking financial risk to start and run a business. In electronics, it may involve repair services, assembly, or product sales.

A written document describing a business idea, target market, operations, marketing strategy, and financial projections. It guides the entrepreneur and is used to obtain loans or support.

The collection and analysis of information about customer needs, competitors, and prices before starting or expanding a business. It helps reduce risk and match products or services to demand.

The calculation of all expenses involved in producing or delivering a product or service, including materials, labour, and overheads. It is used to set a selling price and determine profit.