Gilbert to Teraampere volt per ohm
Gi
TA V/Ω
Conversion History
| Conversion | Reuse | Delete |
|---|---|---|
1 Gi (Gilbert) → 7.95775e-13 TA V/Ω (Teraampere volt per ohm) Just now |
Quick Reference Table (Gilbert to Teraampere volt per ohm)
| Gilbert (Gi) | Teraampere volt per ohm (TA V/Ω) |
|---|---|
| 0.1 | 0.0000000000000795775 |
| 0.5 | 0.0000000000003978875 |
| 1 | 0.000000000000795775 |
| 2 | 0.00000000000159155 |
| 5 | 0.000000000003978875 |
| 10 | 0.00000000000795775 |
| 100 | 0.0000000000795775 |
About Gilbert (Gi)
The gilbert (Gi) equals 10/(4π) amperes — approximately 0.7958 A — and is the CGS-EMU unit of magnetomotive force (MMF) rather than a general-purpose current unit. In magnetic circuit analysis, MMF drives magnetic flux through a reluctance, analogously to how voltage drives current through resistance. A single-turn coil carrying 1 Gi of MMF passes 0.7958 A. In SI, magnetomotive force is measured in ampere-turns (A·T). The gilbert is obsolete but historically significant in transformer design, relay engineering, and magnetic circuit analysis dating from the late 19th century through the 1960s.
A relay coil requiring 2 Gi of MMF to actuate needs about 1.6 A·turn in SI terms. Vintage transformer and relay datasheets from the 1940s–1960s often specify MMF in gilberts.
Etymology: Named after William Gilbert (1544–1603), English physician and natural philosopher who authored De Magnete (1600), the first systematic scientific study of magnetism and electricity, establishing that the Earth itself acts as a giant magnet.
About Teraampere volt per ohm (TA V/Ω)
The teraampere volt per ohm (TA·V/Ω) equals exactly 10¹² amperes, derived from Ohm s law (I = V/R) with a tera- prefix: (volt)/(ohm) = ampere, scaled by 10¹². No natural or engineered system on Earth produces currents remotely approaching one teraampere; the unit exists as a dimensional expression used in extreme theoretical physics, astrophysics (stellar current sheets, pulsar magnetospheres), and unit-conversion pedagogy. The notation makes Ohm s law dimensionally explicit at an extreme scale and serves as a reminder that SI prefixes can be applied consistently to derived units.
One teraampere would require one teravolt across one ohm — voltages found only near highly magnetised neutron stars. The unit is encountered in astrophysics and theoretical electrodynamics rather than any lab or industrial setting.
Gilbert – Frequently Asked Questions
Why is the gilbert approximately 0.7958 amperes and not a round number?
The gilbert equals 10/(4π) amperes because the CGS-EMU system uses a different form of Ampere's law where the factor 4π appears explicitly rather than being absorbed into μ₀. This "unrationalised" form distributes 4π differently in the equations, producing the 1/(4π) factor when converting to SI's "rationalised" system.
What is magnetomotive force and how is it different from regular current?
MMF is the magnetic analogue of voltage — it drives flux through a magnetic circuit the way EMF drives current through an electrical circuit. For a coil, MMF = N × I (turns times current). A 100-turn coil carrying 1 A has 100 ampere-turns of MMF. In CGS, that same MMF would be about 125.7 gilberts.
Who was William Gilbert and why does he deserve a unit?
Gilbert (1544–1603) was physician to Queen Elizabeth I and author of De Magnete (1600), the first true scientific investigation of magnetism. He demonstrated that Earth is a magnet, distinguished magnetic from electrostatic attraction, and coined the word "electricus." He did all this 87 years before Newton's Principia — a genuine pioneer of experimental science.
Where would I find gilberts used today?
Practically nowhere in new designs. You might encounter gilberts in vintage relay and transformer datasheets from the 1940s–1960s, in older American and European magnetic component catalogs, or in classic electrical engineering textbooks. Any modern magnetic circuit analysis uses ampere-turns (A·T) for MMF.
How do I convert gilberts to ampere-turns?
Multiply gilberts by 10/(4π) ≈ 0.7958 to get ampere-turns. Wait — that is backwards. Multiply gilberts by 0.7958 to get amperes for a single-turn coil. For MMF conversion: 1 gilbert = 0.7958 ampere-turns. So a relay spec of 5 Gi needs about 4 ampere-turns to actuate — for instance, 4 turns at 1 A or 8 turns at 0.5 A.
Teraampere volt per ohm – Frequently Asked Questions
Does anything in the universe carry a teraampere of current?
Possibly. Astrophysical jets from active galactic nuclei are theorised to carry currents of 10¹⁷–10¹⁸ amperes — millions of teraamperes — flowing along magnetic field lines spanning thousands of light-years. Pulsar magnetospheres may sustain teraampere-class currents in their polar regions. On Earth, nothing comes remotely close.
Why write TA·V/Ω instead of just teraampere?
The notation makes the derivation from Ohm's law explicit: I = V/R, scaled by tera. It appears in pedagogical contexts showing that SI prefixes apply consistently to derived expressions, and in astrophysics papers where the V/Ω form reminds readers of the physical relationship producing the current — a voltage driving charge through a resistance.
What voltage would you need to push a teraampere through a wire?
Even through a superconductor (zero DC resistance), you would need enormous energy to establish the magnetic field of a teraampere current. Through a 1 Ω resistor, Ohm's law says you would need 10¹² volts (1 teravolt). The power dissipated would be 10²⁴ watts — about 2.6 million times the Sun's total luminosity. The wire would not survive.
How do astrophysical current sheets reach teraampere scales?
In astrophysical jets and magnetospheres, charged plasma flows along magnetic field lines over enormous cross-sections — millions of square kilometers. Even modest current densities, integrated over these vast areas, yield teraampere total currents. The plasma is the conductor, and the "voltage" comes from the rotating magnetic field of the central object.
Is there any practical unit between megaampere and teraampere?
The gigaampere (GA, 10⁹ A) fills that gap but is almost never used. No terrestrial phenomenon or experiment reaches gigaampere levels. The jump from megaampere (achievable in pulsed-power labs) to teraampere (astrophysical only) reflects a genuine gap in nature — there is simply nothing on Earth that produces currents between 10⁶ and 10⁹ amperes.