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
Messages
79
Reaction score
0
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?
 
Physics news on Phys.org
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.
 
Last edited by a moderator:
Hi there, im studying nanoscience at the university in Basel. Today I looked at the topic of intertial and non-inertial reference frames and the existence of fictitious forces. I understand that you call forces real in physics if they appear in interplay. Meaning that a force is real when there is the "actio" partner to the "reactio" partner. If this condition is not satisfied the force is not real. I also understand that if you specifically look at non-inertial reference frames you can...
I have recently been really interested in the derivation of Hamiltons Principle. On my research I found that with the term ##m \cdot \frac{d}{dt} (\frac{dr}{dt} \cdot \delta r) = 0## (1) one may derivate ##\delta \int (T - V) dt = 0## (2). The derivation itself I understood quiet good, but what I don't understand is where the equation (1) came from, because in my research it was just given and not derived from anywhere. Does anybody know where (1) comes from or why from it the...

Similar threads

Back
Top