The formula for drift velocity is given as,
|vd| = eτ/mxE
However, we know that E = V/l
where V refers to the potential difference
l is the length of conductor.
Substituting this value of E in the drift velocity formula, we have:
|vd| = eτ/m(Vl)
- Therefore, the drift velocity is proportional to the potential difference applied across the conductor.
- The length of the conducting wire is inversely proportional to drift velocity. V becomes 2V when the potential difference applied across the conductor is doubled.
- When the conductor’s length is half, l becomes l/2.
Putting these values in the drift velocity equation, we have:
|vd′|=eτ/m(4V/l)
On simplifying the equation further, we get:
|vd′|=4eτ/m(V/l)
We know that eτm(V/l)=|vd|
Substituting this in the above equation we get
|vd′|=4|vd|
Therefore, we can observe that when the potential difference of a conductor is doubled and the length of the conductor is half, the drift velocity increases by four times.
Related Questions
- What is the relation between drift velocity and electric field?
- Define mobility of electron.
- Give two examples of drift velocity.
- Explain the relation between current and drift velocity.
- Define the drift velocity of electrons in a conductor?
- Write the mathematical relation between Mobility And Drift Velocity of charge carriers in a conductor.
- Define relaxation time of the free electrons drifting in a conductor? How is it related to the drift velocity of free electrons? Use this relation to deduce the expression for the electrical resistivity of the material.
- Two conducting wires X and Y of the same diameter but different materials are joined in series across a battery. If the number density of electrons in X is twice that in Y, find the ratio of the drift velocity of electrons in the two wires.
- It is known that the drift velocity of electrons is only a few mm/s for a current of a few amperes. How is it possible that a current is established almost instantaneously when a circuit is closed? For example, a bulb glows as soon as the connection is switched on. Explain.
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