What is electron volt? Before explaining what electron volt definition let us try to give you a concept of electron volt. I start from very basic. In order to know what electron volt definition is. Let’s see below.
The Joule is a unit of energy in the SI system. Energy is measured in joules. However, joule is very large unit while dealing with electrons and other tiny particles. Hence, electron volt is used while dealing with smaller particles like electrons.
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What is Electron Volt? Definition and Concept
Electron volts, like joules, are a unit of energy. This may sound confusing- why two? But think of it this way; length has two possible units- metric (metres) and imperial (inches). We can use either units to measure length and can switch between the two. The same is true of joules and electron volts.
Concept of Electron Volt
The concept of electron volt is very simple. We know the unit of power is watt. W = VI, where V is the voltage and I is the current. Now as I is current, it is nothing but rate of charge transfer. Therefore, instantaneous impression of power would be
Where, q(t) is the amount of charge transferred in time t.
Now energy is expressed as
Where, q is the charge in Coulomb crosses a voltage V volts.
Electron Volt to Joules
From the expression of energy we can write the energy required or work to be done for crossing an electric field of total voltage V by a charge Q coulomb is QV coulomb – volt or joules.
Now we know the charge of an electron is – 1.6 × 10-19 coulomb and consider it has crossed an electric field of total voltage 1 V. Then the total work to be done is charge of electron × 1 V.
This amount of energy is considered as a micro unit of energy called electron-volt.
Electron Volt Definition
Electron volt is defined as the amount of energy one electron gains by moving through a potential difference of one volt. Hence, one electron volt is equal to elementary charge (1.60217657 × 10-19 coulombs (C)) multiplied by one volt. It can be written as
ev = (1.60217657 × 10-19 C) (1V)
Therefore, 1ev = 1.60217657 × 10-19 J.
One electron – volt is the unit of energy in joules which equals to the amount of work to be done for bringing one electron against an electric field of potential difference 1 volt.
This is very tiny or micro unit of energy mainly used for different calculation in atomic and electronic levels. The concept of energy levels in the materials is dealt with this micro unit of energy that is electron volt. Not only the energy of electrons, this unit is also used for all types of energy like thermal, light etc.
Electron Volt Definition and Concept
After going through the above concept of electron volt we can now establish a electron volt definition. I hope you enjoy when reading this article, thank you.