Why does free electrons in metal do not conduct electricity in the absence of electric field?

In a metal, the free electrons move in all directions haphazardly, in the absence of electric field , the average thermal velocity of electrons is zero. Therefore, there is no current in metal in the absence of electric field.

When there is no electric field there is no current in a circuit because?

Why is there no flow of current in the absence of an electric field across it? Metals have free electrons and fixed positive charge. This fixed positve charge in fact act as resistace to the flow of current. The free electones carry current from one electon to other.

Can free electrons flowing through a metal produce magnetic field if there is no current flow in it?

Free electrons always keep on moving in a conductor even when no magnetic force act on them in a magnetic field unless a current is passed through it.

What happens when a conductor is placed in an external electric field?

When an electric field E is applied to a conductor, free charges inside the conductor move until the field is perpendicular to the surface. The free charge has been brought to the conductor’s surface, leaving electrostatic forces in equilibrium. A conductor placed in an electric field will be polarized.

Why free electrons are present in metals?

The particles in a metal are held together by strong metallic bonds. Metals atoms have loose electrons in the outer shells, which form a ‘sea’ of delocalised or free negative charge around the close-packed positive ions. These loose electrons are called free electrons.

Why do metals have no electric field?

Charges have maximum freedom of movement within a conductor, and this gives way to there being no electric field within the conductor. Thus, the electrons in the metal are going to move toward the left (because field lines are drawn in the direction of positive charges).

When an electric current is passing through a conductor there is no electric field produced because the conductor is?

When an electric current is passing through a conductor, there is no electric field produced because the conductor is. When an electric current is passed through a metallic conductor, heat is produced.

Can current flow without electric field?

If there are no sources of electric current, such as battery, then the electrons in the conductor will redistribute until the electricfield in the conductor is reduced to zero, at which point these transient electric currents cease. Thus in static systems, the electric field inside conductors is zero.

What happens to free electrons?

The electrons that are free to move will gain some speed. Since they have a negative charge, they move in the direction opposite that of the electric field. The current i is defined to have a positive value in the direction of flow of positive charges.

Where do free electrons go?

Energy is required to make the free electrons travel in one direction. An electric cell (often called a battery) can supply this energy and make free electrons move in a metal conductor connected between its two terminals. Electrons flow from the negative terminal through the conductor to the positive terminal.

Why the electric field inside a conductor placed in an external electric field is always zero?

A conductor is a material that has a large number of free electrons available for the passage of current. Hence in order to minimize the repulsion between electrons, the electrons move to the surface of the conductor. Hence we can say that the net charge inside the conductor is zero.

What is external field in physics?

Introduction. When an external field (e.g., electric and gravitational fields) is applied to a suspension of charged colloidal particles in a liquid, the external field accelerates the particles and at the same time a viscous force exerted by the liquid on the particles tends to retard the particles.

Why is the electric field inside a conductor zero?

So the free charge inside the conductor is zero. So the field in it is caused by charges on the surface. Since charges are of the same nature and distribution is UNIFORM, the electric fields cancel each other. Consider a Gaussian surface inside the conductor. Charge enclosed by it is zero (charge resides only on surface).

What is the free charge inside a conductor?

So the free charge inside the conductor is zero. So the field in it is caused by charges on the surface. Since charges are of the same nature and distribution is UNIFORM, the electric fields cancel each other.

What happens to electrons in a conductor at low temperatures?

Many conductive materials become perfectly conductive (this is called superconductivity) at extremely low temperatures. While the normal motion of “free” electrons in a conductor is random, with no particular direction or speed, electrons can be influenced to move in a coordinated fashion through a conductive material.

What is the electric flux of a conductor with zero charge?

Since charges are of the same nature and distribution is UNIFORM, the electric fields cancel each other. Consider a Gaussian surface inside the conductor. Charge enclosed by it is zero (charge resides only on surface). Therefore electric flux =0 Furthermore, electric flux = electric field * area. Since area cannot be zero, electric field is zero