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Drift Velocity is considered one of the most asked concept.
16 Questions around this concept.
The drift velocity of the electrons is v when current I is flowing through it.If both the radius and currents are doubled then drift velocity will be
The drift velocity of electrons for a conductor connected in an electrical circuit is . The conductor is now replaced by another conductor with the same material and the same length but doubles the area of the cross-section. The applied voltage remains the same. The new drift velocity of electrons will be
A electric current of 16 A exists in a metal wire of cross section and length 1m. Assuming one free electrons per atom. The drift speed of the free electrons in the wire will be
( Density of metal atomic weight )
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If E denotes electric field in a uniform conductor and the corresponding drift velocity of free electrons in the conductor then which of the following graph is correct ?
At room temperature, copper has free electron density of . The electron drift velocity in a copper conductor of cross-sectional area and carrying a current of 5.4 A, will be
Two wires A and B of the same material, having radii in the ratio 1:2 and carry currents in the ratio 4 :1. The ratio of drift speed of electrons in A and B is
Relaxation time (): The time interval between two successive collisions of electron with the Positive ions.
Mean Free path: The path between two consecutive collisions is called free path. The average length of these free paths is called “Mean Free Path”.
Drift velocity
Drift velocity is the average velocity that a particle such as an electron attains in a material due to an electric field.
$
v_d=\frac{-e \vec{E}}{m} \tau
$
Where $v_d$ is the drift velocity, E is the electric field applied, e and m are the charge and mass of electrons respectively and $\tau$ is the relaxation time.
- Vd is directly proportional to $\mathrm{E}: v_d \alpha E$ when the temperature is constant, the greater the electric field larger will be the drift velocity
Drift velocity and current
$
\begin{aligned}
& J=\frac{I}{A}=\frac{n e A v_d}{A} \\
& J=n e v_d
\end{aligned}
$
Drift velocity varies inversely with the area of cross-section
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