Part VII Measurement of Electricity
United Kingdom
| 1. | (a) AMPERE | F1for which the symbol “A” is used, is the SI unit of electric current, defined by taking the fixed numerical value of the elementary charge e to be 1.602 176 634 × 10-19 when expressed in the unit C, which is equal to A s, where the second is defined by taking the fixed numerical value of the caesium frequency ΔvCs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be 9 192 631 770 when expressed in the unit Hz, which is equal to s-1. |
| (b) OHM | is the electric resistance between two points of a conductor when a constant potential difference of 1 volt, applied between the two points, produces in the conductor a current of 1 ampere, the conductor not being the seat of any electromotive force. | |
| (c) VOLT | is the difference of electric potential between two points of a conducting wire carrying a constant current of 1 ampere when the power dissipated between these points is equal to 1 watt. | |
| (d) WATT | is the power which in one second gives rise to energy of 1 joule F2, where the second has the meaning given in the definition of “AMPERE”. | |
| 2. | Kilowatt | = 1000 watts. |
| Megawatt | = one million watts. |
Annotations
Textual amendments
- F1
Words in Sch. 1 Pt. 7 substituted (13.6.2020) by The Weights and Measures Act 1985 (Amendment) and Units of Measurement Regulations 1986 (Amendment) Regulations 2019 (S.I. 2019/1211), regs. 1(b), 2(a)
- F2
Words in Sch. 1 Pt. 7 inserted (13.6.2020) by The Weights and Measures Act 1985 (Amendment) and Units of Measurement Regulations 1986 (Amendment) Regulations 2019 (S.I. 2019/1211), regs. 1(b), 2(b)