Effect of Potential Difference on Drift Velocity of Charge Carriers in Copper Wire

Introduction:
In a copper wire, the charge carriers are electrons. These electrons move randomly in the wire with a thermal velocity. When a potential difference is applied across the wire, these electrons experience a net force and start moving in a particular direction. This net motion of electrons is called the drift velocity.

Effect of Potential Difference:
When the potential difference across the copper wire is increased, the electric field inside the wire also increases. This electric field exerts a force on the electrons, which increases their drift velocity. This means that the electrons move faster in the direction of the electric field.

Explanation:
The relationship between the drift velocity and the electric field is given by the following equation:

v = (eEτ)/m

where,
v = drift velocity,
e = charge of an electron,
E = electric field,
τ = relaxation time,
m = mass of an electron.

From the above equation, it is clear that the drift velocity is directly proportional to the electric field. Therefore, when the potential difference is increased, the electric field and hence the drift velocity of the electrons also increase.

Conclusion:
Hence, we can conclude that when the potential difference across the copper wire is increased, the drift velocity of the charge carriers (electrons) also increases.