What do you mean by drift velocity?
Drift velocity is the average velocity with which electrons ‘drift’ in the presence of an electric field. It’s the drift velocity (or drift speed) that contributes to the electric current. In contrast, thermal velocity causes random motion resulting in collisions with metal ions.
On what factors drift velocity depends?
The drift velocity is known to be primarily dependent on the applied voltage and another property on which it depends is the molecular structure of the wire and hence the material of the conductor. Slight temperature dependence is also observed.
How do you prove drift velocity?
When electrons with density n and charge Q causes a current ‘I’ to flow through a conductor of cross-sectional area A, Drift velocity v can be calculated through the formula I = nAvQ.
Does resistance affect drift velocity?
From the formula v=IenA, we can conclude that overall drift velocity in circuit decreases by using a larger resistor (as it reduces the current). Having constant current density J, electrical field in wire is Ew=Jρw and resistor Er=Jρr.
How are drift velocity and resistance related?
Relation between Drift Velocity, Current Density and Resistivity. We know that the value (m / n e2 ԏ) is the resistivity of the conductor. Hence V = ρ L / A * I. The mobility of a moving charge carrier in a conducting material is the magnitude of the drift velocity per unit electric field.
What is difference between drift velocity and average velocity?
Dear Sukumar, Absence of electric field all the electrons are traveled in random direction with different velocity when the presence electric field all the electrons are acquired average velocity and move with same direction that is opposite to applied field direction such average velocity is called drift velocity.
How does drift velocity depend on electric field?
Yes, it does depend upon the length of the wire. Drift velocity (vd) can be found using this formula, vd=eEτm (where e is the charge on an electron, E is the electric field inside the wire, τ is the average time between the collision of electrons, and m is the mass of an electron).
What is drift velocity directly proportional to?
Drift velocity is directly proportional to current. It is also directly proportional to the magnitude of the external electric field in a resistive material. Drift velocity can be expressed in terms of Ohm’s law. u = µE.
How drift velocity varies with change in temperature and electric field?
ii) As the temperature is increased, drift velocity of electrons in a metallic conductor increases. Therefore, as the temperature of the metallic conductor increases, the collision between the electrons and ions increases, resulting in decrease in the relaxation time. Thus, the drift velocity decreases.
What is the effect of temperature on drift velocity?
The drift velocity is also slightly temperature-dependent: an increase in temperature causes atoms to vibrate more, which increases the number of collisions electrons have on their way through the wire and decreases the drift velocity.
How is drift velocity in a conductor affected with rise in temperature?
Drift velocity is dependent on temperature i.e. When the temperature is increased the electrons become kinetically excited means rise in temperature causes atoms to vibrate more, which increases the number of collisions electron have on their way through the wire and decreases the drift velocity.
What causes a conductors speed to increase?
Electric drift Free electrons in a conductor follow a random path. Without the presence of an electric field, the electrons have no net velocity. When a DC voltage is applied, the electron drift velocity will increase in speed proportionally to the strength of the electric field.