- Definition of Electron Volt: An electron volt is defined as the energy needed to move one electron against an electric field of one volt.
- Power Calculation: Power (W) is calculated as the product of voltage (V) and current (I).
- Energy Expression: Energy is calculated as the charge (q) in coulombs times the voltage (V).
- Charge of Electron: The charge of an electron is -1.6 × 10^-19 coulombs.
- Applications of Electron Volt: Electron volts are used for various energy calculations at atomic and electronic levels, as well as for thermal and light energy.
An electron volt is the energy one electron gains when it moves through 1 volt. Start from ordinary circuit power: the watt.
W = VI, where V is the voltage and I is the current.
Current (I) is charge per unit time, so instantaneous power is:
Here q(t) is the charge transferred in time t.
Energy then follows as
where q is the charge in coulomb that crosses a potential of V volts. One coulomb-volt equals one joule.
The work to take charge Q coulomb through an electric field of potential V is QV joule. The electron charge is -1.602176634 × 10-19 coulomb (exact in SI; many textbooks still round this to 1.6 with the same power of ten). If that charge moves through 1 V, the energy is |e| times 1 V.
That quantity is one electron volt, a small energy unit.
Definition of Electron – volt
One electron-volt is the energy, in joule, equal to the work to move one electron through an electric field of potential difference 1 volt.
It is a small unit used for atomic and electronic calculations, including electron energy levels in solids. The same unit is also used for thermal energy and photon energy at that scale.
