Table of Contents
- 1 How then is current established almost the instant a circuit is closed?
- 2 How is drift speed related to current?
- 3 Why then do the electrons acquire a steady average drift speed?
- 4 Is there a net field inside the cell when the circuit is closed and a steady current passes through?
- 5 How does electric current flow in a circuit?
- 6 How current is established in a conductor?
- 7 Why current is produced instantly when voltage is applied on conductor?
- 8 How do electrons move from one end of the conductor?
How then is current established almost the instant a circuit is closed?
then 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. This is possible because an electric field is set up in the circuit as soon as it is closed, almost with speed of light.
Current is the flow of free charges, such as electrons and ions. Drift velocity vd is the average speed at which these charges move. Current I is proportional to drift velocity vd, as expressed in the relationship I=nqAvd I = nqAv d . Here, I is the current through a wire of cross-sectional area A.
How can electricity be so fast even if electrons have a very slow drift speed?
The flow of electrons is proportional to the voltage which is the electrical force or “push” to make them move. They no longer drift , they are pushed by the voltage pressure to move faster.
How is current established?
When a metal wire is subjected to electric force applied on its opposite ends, these free electrons rush in the direction of the force, thus forming what we call an electric current.”
Why then do the electrons acquire a steady average drift speed?
The electron collides with the positive ion and loses its speed. But it again starts accelerating under the influence of the electric field, gains speed, collides with the positive ion, and loses its speed. This process continues. Thus, the electron has acquired a steady average drift speed.
Is there a net field inside the cell when the circuit is closed and a steady current passes through?
Yes there is a net electrical field inside a cell from positive end of battery to negative end. This electrical field is produced due to electode potential between positive and negative terminal.
What is drift velocity establish the relation between drift velocity and current?
v=aτ where v is the drift velocity, a is the acceleration and τ is the average relaxation time between two successive collisions. N=nV where N is the total number of electrons, n is the number density of electrons and V is the volume. This is the required relation between the current and the drift speed.
How are electrons so fast?
It is the electromagnetic field which travels in the circuit at near the speed of light that is resposible for it. After turn on the light, electron only acquires a little speed in addition its thermal speed.
How does electric current flow in a circuit?
The direction of an electric current is by convention the direction in which a positive charge would move. Thus, the current in the external circuit is directed away from the positive terminal and toward the negative terminal of the battery. Electrons would actually move through the wires in the opposite direction.
How current is established in a conductor?
When an electric current flows in a conductor, it flows as a drift of free electrons in the metal. Electricity flows easily through a conductor because the electrons are free to move around in the object. Whenever there is a movement of electrons through a conductor, an electric current is created.
What is the electron drift speed in a conductor?
[SOLVED] The electron drift speed is small and the charge of the electron is also small but still, we obtain large current in a conductor. This is due to The electron drift speed is small and the charge of the electron is also small but still, we obtain large current in a conductor.
Why doesn’t electric current travel at the speed of electrons?
Well, this is because the electric current doesn’t travel at the speed of electrons. It is actually the disturbance that is transferred forward, and that too with tremendous speeds, even though the electrons are slower than a snail (That’s surprisingly true)! Imagine having a thin long tube, full of marbles, one after the other, open at both ends.
Why current is produced instantly when voltage is applied on conductor?
The conductor is full of ‘’free electrons”. When we switch on the voltage the electric field is established in the entire conductor at the speed of light and all free electrons acquire drag velocity immediately and hence we get the current instantly .
How do electrons move from one end of the conductor?
Establishment of a current does not require individual electrons to move from one end of the conductor to the other. Each free electron in the conductor accelerates due to the effect of the electric field until it collides with a positive ion of the metal and loses its drift speed.