SI: ampere and coulomb Mystery Cache

The International System of Units (SI), commonly known as the metric system, is the international standard for measurement. The SI plays an essential role in international commerce and is commonly used in scientific and technological research and development. This cache is part of the SI geoart that allows you to learn about the SI units. Visit the introduction cache to learn more about this geoart.

Electric current: ampere (A)

The ampere is the SI base unit of electric current. The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed one metre apart in vacuum, would produce between these conductors a force equal to 2×10−7 newtons per metre of length.

Electric charge: coulomb (C)

The coulomb is the SI derived unit of electric charge. It is the charge transported by a constant current of one ampere in one second.

The elementary charge, or the electric charge carried by a single proton, is defined to be exactly 1.602176634×10⁻¹⁹ coulombs. Consequently, the coulomb is equivalent to the charge of approximately 6.242×10¹⁸ protons.

Another subatomic particle, the electron, carries negative one elementary charge. Therefore, -1 C is equivalent to the charge of 6.242×10¹⁸ electrons.

This Geocache

One mole of electrons moved through a boundary in 183432 ms. What’s the magnitude of the electric current in amperes? Round it to an integer to get ABC.

Ampere balance is an electromechanical apparatus for the precise measurement of the ampere. However, it has a major weakness that its accuracy is limited by the measurement accuracy of its coils. B. P. Kibble invented a successor that removes this source of inaccuracy. In which year was the successor device invented? Divide this number by 5 and add 220 to get DEF.

Final coordinates: N 39° 08.ABC W 077° 08.DEF

You can validate your puzzle solution with certitude.

Cache container is a baby-nano with tiny log sheet. A pair of tweezers is mandatory for log retrieval. To conserve space, please omit the date and write the first two letters of your username only.

Some hides are located along a road without sidewalk. For your safety, please walk on the grass out of the car lanes, and avoid going at night without wearing a safety vest.

Lists of Caches in SI geoart

0. introduction
1. second and hertz
2. metre
3. kilogram
4. m/s and km/h
5. mole
6. radian and steradian
7. m/s² and newton
8. m² and pascal
9. joule and watt
10. ampere and coulomb
11. volt and farad
12. ohm
13. kelvin
14. candela, lumen, and lux
15. bushel
16. foreword & afterword
17. prize distribution