What is Electron and Field intensity,

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An electron is a subatomic particle that is one of the fundamental building blocks of matter. It is a negatively charged particle, meaning it carries an elementary electric charge. Here are some key characteristics and properties of electrons:

Electron as a Subatomic Particle: Electrons are subatomic particles that orbit the nucleus of an atom. They carry a negative elementary electric charge, which is a fundamental property of electrons. This charge is denoted by "e," and its magnitude is approximately 1.6 x 10^-19 coulombs.

Mass of an Electron: The mass of an electron is not a fixed value; it depends on its velocity according to Albert Einstein's theory of relativity. This theory, specifically the theory of special relativity, states that as an object with mass (like an electron) moves at speeds close to the speed of light (denoted by "c," which is approximately 3.00 x 10^8 m/s), its mass increases.

Relativistic Mass: The equation you provided, often referred to as the relativistic mass formula, describes how the mass (denoted as "m") of an electron changes with its velocity ("v"). The equation is given as:

  • "m" represents the relativistic mass of the electron.

  • "m₀" represents the rest mass of the electron, which is its mass when it's at rest or moving at very low velocities.

  • "v" is the velocity of the electron.

  • "c" is the speed of light in free space.

Rest Mass of Electron: The rest mass of an electron, denoted as "m₀," is the mass it has when it is not moving (v = 0). This value is approximately 9.1 x 10^-31 kilograms.

Effect of Relativity on Mass: The equation shows that as the velocity of the electron increases, the denominator of the fraction (√(1 - v²/c²)) decreases. As a result, the mass of the electron increases. When the electron approaches the speed of light (v ≈ c), the denominator approaches zero, and the mass appears to approach infinity.

This phenomenon is a fundamental concept in relativistic physics. It implies that as objects with mass, such as electrons, approach the speed of light, it becomes increasingly difficult to accelerate them further because their mass increases significantly. This is one of the reasons why particles with mass cannot reach or exceed the speed of light in our universe, as predicted by Einstein's theory of special relativity.

Field Intensity: The electric field intensity is a measure of the strength of an electric field at a given point. It is defined as the force per unit charge that would be experienced by a small, point charge placed at that point. Electric field intensity is a vector quantity, meaning that it has both magnitude and direction.

The electric field intensity of a uniform field is constant, meaning that it has the same magnitude and direction at every point in the field. An example of a uniform electric field is the field between the parallel plates of a capacitor.

The electric field intensity of a radial field decreases with distance from the central charge. An example of a radial electric field is the field around a point charge.

The electric field intensity at a given point can be calculated using the following equation:

E = F / q

E = F / q = k * q / r^2

E = 9.0 x 10^9 N m^2/C^2 * 1 C / (1 m)^2

E = 9.0 x 10^9 N/C


  • E is the electric field intensity (N/C)

  • F is the force (N) that would be experienced by a small, point charge placed at that point

  • q is the charge of the small, point charge (C)

The SI unit of electric field intensity is Newton per coulomb (N/C). It is also equivalent to volts per meter (V/m).

Here is an example of how to calculate the electric field intensity at a given point:

Suppose we have a point charge of +1 C placed at the origin. The electric field intensity at a distance of 1 meter from the origin is given by:


  • k is Coulomb's constant (9.0 x 10^9 N m^2/C^2)

  • q is the charge of the point charge (+1 C)

  • r is the distance from the point charge (1 m)

Therefore, the electric field intensity at a distance of 1 meter from the point charge is 9.0 x 10^9 N/C.

Electric field intensity is an important concept in physics and engineering. It is used to design and analyze electrical devices, such as capacitors, resistors, and transistors. It is also used to study the behavior of charged particles in electric fields.