What is the unit of measurement of electric energy?

One degree of electricity is a unit of energy. The energy of one degree of electricity = one degree of electricity (common sense) 1000 mA rechargeable battery =3.7V× 1000 mA× 1 hour = 3.7W/ hour.

(Generally, the voltage of mobile phone battery is 3.7V) The number of times of one charge = 1kWh÷3.7W/ hour = 1000÷3.7=270.3 times, so the battery with 1000 mAh can be charged 1 270.3 times.

A constant current passes through two parallel straight lines with infinite length and negligible circular cross-section, and the distance between the two straight lines in vacuum is 1 meter. When the force generated between two wires per meter is equal to 2× 10-7 Newton, the current passing through the wires is specified as 1 amp.

Extended data:

Ampere is related to watt balance and unit volt and ohm in ohm's law. But also have their own applications in Josephson effect and quantum Hall effect. The technique of establishing one ampere has been able to reach the approximate error of 10.

Annular current can be regarded as multiple small linear currents. For each small linear current, the direction of magnetic induction intensity on the central axis of annular current can be determined by ampere rule of linear current. The direction of the magnetic induction line on the central axis of the annular current is obtained by superposition.

Ampere's law of linear current is basic. Ampere rule of annular current can be deduced from ampere rule of linear current. The ampere rule of linear current also applies to the magnetic field generated by linear motion of charge. At this time, the direction of current is the same as that of positive charge.