Biot to Coulomb per second
Bi
C/s
Conversion History
| Conversion | Reuse | Delete |
|---|---|---|
1 Bi (Biot) → 10 C/s (Coulomb per second) Just now · Rounding: Up to 8 significant figures | Recalculate this conversion using your current rounding settings. |
Quick Reference Table (Biot to Coulomb per second)
| Biot (Bi) | Coulomb per second (C/s) |
|---|---|
| 0.1 | 1 |
| 0.5 | 5 |
| 1 | 10 |
| 5 | 50 |
| 10 | 100 |
| 30 | 300 |
| 100 | 1,000 |
Results rounded to a maximum of 8 significant figures
About Biot (Bi)
The biot (Bi) is the base unit of electric current in the centimeter-gram-second electromagnetic (CGS-EMU) system. Under the traditional pre-2019 CGS-to-SI mapping retained by this converter, one biot corresponds to 10 amperes. It is defined as the current in a pair of parallel conductors 1 cm apart that produces a force of 2 dynes per centimeter length — the CGS-EMU analogue of the former force-based SI ampere definition. The biot, EMU of current, and CGS e.m. unit are exactly the same current unit within CGS-EMU. Their 10 A relationship is a historical conversion convention rather than an exact physical conversion to the post-2019 SI, in which vacuum permeability is experimentally determined. The biot is essentially obsolete in modern practice, but it appears in older physics literature and classical electrodynamics textbooks alongside the dyne, gauss, and oersted.
Under the traditional mapping used here, 1 Bi corresponds to 10 A — roughly the draw of a domestic electric kettle. References to the biot appear primarily in historical or theoretical contexts, not modern instrumentation.
Etymology: Named after Jean-Baptiste Biot (1774–1862), French physicist who, with Félix Savart, established the Biot–Savart law describing the magnetic field generated by a steady electric current.
About Coulomb per second (C/s)
The coulomb per second (C/s) is a derived SI expression for electric current that makes the physical definition explicit: one ampere is exactly one coulomb of charge passing a point per second. The relationship I = Q/t links current (A), charge (C), and time (s). While C/s and A are numerically identical and dimensionally equivalent, the C/s form appears in physics textbooks and dimensional analyses where the derivation from charge and time is instructive rather than treating the ampere as primitive. In calculations tracking charge accumulation — capacitor discharge, electroplating, or battery coulomb-counting — expressing current in C/s clarifies the unit chain.
A capacitor delivering 1 C of charge over 1 second discharges at exactly 1 C/s = 1 A. A 500 mA USB charger transfers 0.5 C of charge each second.
Biot – Frequently Asked Questions
Why does this converter map one biot to 10 amperes?
The CGS-EMU system defines its base units using centimeters, grams, and seconds instead of meters, kilograms, and seconds. Under the former force-based SI ampere definition, converting the force between parallel currents made 1 Bi exactly 10 A. Since the 2019 SI redefinition, vacuum permeability is experimentally determined, so this converter retains 10 A as the stable traditional CGS-to-SI reference mapping rather than presenting it as an exact modern physical conversion.
Who was Jean-Baptiste Biot and why does he have a current unit?
Biot was a French physicist (1774–1862) who co-discovered the Biot–Savart law in 1820, describing how electric current generates a magnetic field in space. This was one of the foundational results linking electricity to magnetism. The CGS community honored him by naming their electromagnetic current unit after him.
Does anyone still use the biot in modern physics?
Essentially no. Even theorists who prefer CGS units typically use Gaussian units rather than pure CGS-EMU. The biot appears mainly in textbook conversion tables, historical physics papers, and graduate-level electrodynamics courses that teach multiple unit systems for pedagogical reasons.
How do I convert between biots and amperes?
Multiply biots by 10 to get amperes; divide amperes by 10 to get biots. A 30 A circuit carries 3 Bi; a 0.5 Bi current is 5 A. It is one of the simplest unit conversions in physics — just move the decimal point one place.
What is the Biot-Savart law and how does it relate to the biot unit?
The Biot-Savart law calculates the magnetic field produced by a small segment of current-carrying wire at any point in space. In CGS-EMU, it uses biots for current and gauss for the field. In SI it uses amperes and teslas. The law itself is fundamental — it is used to design MRI magnets, motors, and particle accelerators.
Coulomb per second – Frequently Asked Questions
Why bother writing coulombs per second when it is just amperes?
In dimensional analysis and physics derivations, C/s makes the relationship between charge and current explicit. When you are computing how much silver an electroplating bath deposits (Faraday's law), writing current as C/s reminds you that charge = current × time, which directly gives the mass deposited.
How many electrons is one coulomb?
One coulomb is approximately 6.242 × 10¹⁸ electrons — about 6.2 quintillion. At 1 C/s (1 A), that many electrons pass a point in your wire every single second. A USB cable charging your phone at 2 A carries 12.5 quintillion electrons per second. The numbers are staggering but the charges are tiny.
Is coulombs per second used in any real-world instrument or specification?
Not directly — every instrument reads in amperes or milliamperes. But coulomb-counting battery fuel gauges internally track charge in coulombs by integrating current over time: ∫I dt. The C/s framing appears in battery management system firmware and electrochemistry literature where charge balance matters.
How does Faraday's law of electrolysis use coulombs to predict metal deposition?
Faraday discovered that the mass of metal deposited at an electrode is directly proportional to the total charge passed (in coulombs). For silver, 107.87 grams deposit per 96,485 C (one Faraday). So a 10 A electroplating bath running for 1 hour passes 36,000 C and deposits about 40 g of silver. Thinking in C/s makes the calculation: current × time × atomic weight / (valence × 96,485).
How does coulomb counting work in battery management systems?
A shunt resistor or Hall sensor continuously measures current flowing in and out of the battery. The BMS integrates this current over time (summing C/s × Δt) to track net charge. Drift and measurement errors accumulate, so smart BMS designs periodically recalibrate against voltage-based state-of-charge estimates.