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Every element consists of Atoms which are made up of negatively charged electrons and nucleus. Within the atom, these negatively charged electrons flow in random ways. Electricity is created by the movement of electrons. The average velocity of electrons in a substance, however, becomes zero due to their random motion. When a potential difference is given to the ends of a material, electrons within the material gain a certain amount of velocity, resulting in a modest net flow in one direction.
Drift Velocity is the velocity which causes electrons to travel in a specific direction.
Drift Speed
The average velocity with which free electrons drift towards the positive end of the wire in the presence of external electric field is known as drift velocity.
Drift Speed Formula
Drift speed formula is used to determine the drift velocity which is given as
I=n×A×v×Q
Here,
I = current
A = area of conductor’s electric field
Q = charge of electrons
n = number of electrons
v = velocity of electron
When the applied external electric field intensity is increased, the electrons move more quickly towards the direction of the applied electric field, which is positive.
Drift Speed of Electron
In the absence of an electrical field, electrons move at random, as we all know. However, when electrons travel in the presence of an electric field and in its direction, the net speed of their motions is referred to as Drift speed (velocity) of the electrons. If we have to define it correctly, it is “the average velocity obtained by charged particles in a material due to the impact of an electronic field known as Drift velocity.” The concept of motion is based on the random movement of free electrons in a conductor.
Drift speed of electrons can be determined using the random motion of free electrons travelling about in the conductor. As a result of this field, the electrons continue to travel randomly, but their random motion will shift them towards a greater potential. This shows that the electrons are moving towards the higher potential end of the wire. As a result, each electron’s net velocity will be toward the conductor’s end. The current created by the mobility of electrons inside a conductor is known as Drift current.
Net Velocity
Metals with free electrons travelling randomly at 0 degrees Celsius have some electrons. When an electric potential is added, they will flow towards a positive potential, but if they collide with other atoms, they will bounce back and lose kinetic energy. However, because of the electric field, electrons will accelerate and collide again, and this circumstance will occur numerous times.
Relation Between Drift Velocity and Electric Current
Drift velocity is in proportion with the current. And also, drift velocity is directly proportional to the magnitude of an electric field.
Hence, the relation between drift velocity and electric current is given as
u = mu×E
u = drift velocity
E = electric field
mu = electron mobility
Electricity travels at the speed of light. It has nothing to do with the electrons’ drift velocity in the substance. As a result, the material may vary, but the speed of electric current is always based on the speed of light.
Every conductor has free electrons that move about at random. A current is created when electrons go in one direction due to the Drift velocity. An electron’s drift velocity is often measured 10-1 m/s. As a result, an electron travelling at this speed will take 17 minutes to transit through a one-meter conductor.
Relaxation Time
The relaxation time is the duration between two successive collisions of electrons with positive ions inside the metallic lattice.
Relation between Drift Velocity and Relaxation Time
Electrons travel randomly as gas molecules in a conductor. They collide with each other during this motion. The electron’s relaxation time is the time it takes for it to recover to its initial equilibrium value following a collision. This relaxation time is related to the strength of the applied external electric field. The longer the electric field lasts, the longer it takes for electrons to re-establish equilibrium after the field is withdrawn.
The duration for which an electron can move freely between subsequent collisions with other ions is also known as relaxation time.
Relation between drift velocity and relaxation time is given as
V=eE/mT
Here,
V = drift velocity
T = relaxation time
eE = charge*electric field
Conclusion
Drift Velocity is the velocity which causes electrons to travel in a specific direction.
Drift speed formula is used to determine the drift velocity which is given as
I=n×A×v×Q
Drift velocity can be determined using the random motion of free electrons travelling about in the conductor.
Drift velocity is in proportion with the current. And also, drift velocity is directly proportional to the magnitude of an electric field.
An electron’s drift velocity is often measured 10-1 m/s.
The relaxation time is the duration between two successive collisions of electrons with positive ions inside the metallic lattice.
Relation between drift velocity and relaxation time is given as
V=eE/mT
The relation between drift velocity and electric current is given as
u = mu×E
