During the discharge of a battery, the current in the circuit flows from the positive to the negative electrode. According to Ohm’s law, this means that the current is proportional to the electric field, which says that current flows from a positive to negative electric potential.

Electric current is flow of electrons in a conductor. The force required to make current flow through a conductor is called voltage and potential is the other term of voltage. For example, the first element has more positive charges, so it has higher potential.

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.

The amount of current does depend on the cross section of a wire, that is, the for a given conductor, the resistance is doubled as the cross-sectional area is halved. The EMF provided by the voltage allows for current to flow.

There are 4 different factors which affect resistance:

• The type of material of which the resistor is made.
• The length of the resistor.
• The thickness of the resistor.
• The temperature of the conductor.

There are several factors that affect the resistance of a conductor;

• material, eg copper, has lower resistance than steel.
• length – longer wires have greater resistance.
• thickness – smaller diameter wires have greater resistance.
• temperature – heating a wire increases its resistance.

Resistance is proportional to how much pressure is required to achieve a given flow, while conductance is proportional to how much flow occurs for a given pressure. Conductance and resistance are reciprocals. The resistance of an object depends on its shape and the material of which it is composed.

Silver