Electric charge is the fundamental physical property of matter that causes it to experience a force when placed in an electromagnetic field. Understanding its measurement is the first step in studying Electricity (Class 10 Physics).
In nature, electric charge is always 'quantized'. This means you can only have charges that are whole-number multiples of the charge of a single electron (e.g., 1e, 2e, 3e). You cannot have 1.5e.
The SI unit of electric charge is the Coulomb, denoted by the capital letter C.
It is named in honour of the French physicist Charles-Augustin de Coulomb, who discovered Coulomb's Law (the law describing the electrostatic force of attraction and repulsion).
One Coulomb is a massively large quantity of charge. The charge possessed by a single electron is extremely small: -1.6 × 10⁻¹⁹ C.
To make up exactly 1 Coulomb of negative charge, you would need approximately 6.24 × 10¹⁸ electrons (that is 6.24 quintillion electrons!).
Electric charge (Q) is related to Electric current (I) and time (t) by the formula: Q = I × t
Therefore, 1 Coulomb can also be defined as the amount of charge that passes through a conductor when a current of 1 Ampere flows for 1 second (1 C = 1 A·s).
The two types of electric charges are **Positive** (carried by protons) and **Negative** (carried by electrons). Like charges repel each other, and opposite charges attract.
1 Joule is Equal to — Definition and Conversions
Learn what 1 Joule is equal to in Physics. 1 J = 1 N·m = 1 kg·m²/s². Understand energy conversions to calories, eV, and ergs for Class 9 and Class 11.
1 Kilowatt is Equal to How Many Watts and Joules per Second?
1 kilowatt (kW) is equal to 1000 watts (W) or 1000 joules per second (J/s). Learn the conversion with examples and applications.
1 kWh is Equal to How Many Joules? — Kilowatt-Hour Explained
1 kWh (kilowatt-hour) is equal to 3,600,000 joules (3.6 MJ). Learn the conversion formula, derivation, and practical examples of kWh.
1 Micron to mm — How Many Millimetres is 1 Micron?
1 micron (micrometre, μm) is equal to 0.001 mm. Learn the conversion between microns, millimetres, metres, and nanometres with examples.
1 Nanometre (nm) Is Equal to How Much?
1 nanometre (nm) = 10⁻⁹ metres = 10 angstroms = 1000 picometres. Complete nanometre unit conversion table with examples from physics and chemistry.
Turn this guide into revision flashcards, a practice exam, or an AI-generated podcast — free, no signup required.