What Force Causes Drift Velocity Increase in Wires of Different Diameters?

AI Thread Summary
When current flows from a wire of greater diameter to one of lesser diameter, the drift velocity of electrons increases due to the inverse relationship between drift velocity and cross-sectional area. The equation I = venA illustrates that as the area (A) decreases, the drift velocity (v) must increase to maintain a constant current (I). This phenomenon is explained by the conservation of energy rather than an external force, drawing a parallel to Bernoulli's principle in fluid dynamics. The discussion emphasizes that the increase in drift velocity is a natural consequence of the geometry of the conductor. Understanding this relationship is crucial for analyzing current flow in wires of varying diameters.
Himal kharel
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consider two wires of different diameter. when current enters from that of greater diameter to lesser diameter drift velocity increases. which force causes it to increase?
 
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it is really simple.
we have,current(I) through a conductor of the crossectional area of A is the product of the drift velocity(v) of the moving charges ,the area(A) and number of electrons(n)*the charge of a electron(e).hence
I=venA
or, v=I/(enA)
this relation shows that drift5 velocity is inversely proportional to the area of crosssection of the conductor.Hence if area decreases drift velocity increases.
HOPE THIS HELPS HIMAL
 
I don't think there's an external force involved, as it seems you have in mind, rather conservation of energy causes the drift velocity to increase, similar to http://en.wikipedia.org/wiki/Bernoulli%27s_principle" in fluid dynamics.
 
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