Current, Voltage and Resistance are chathamtownfc.netmon terms the are used to describe electricity in circuits.

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Current is the amount of fee that passes v a allude in a conductor every second. The price for existing is I and also the unit is amps (A).

Voltage (potential difference) is the work done to move a charge versus an electrical field between two points. The symbol because that voltage is V and the unit because that voltage is volts (V)

Resistance is a measure up of how difficult it is for existing to circulation through a material. The symbol for resistance is R and resistance is measured in ohms (Ω). There space several factors that impact the resistance that a conductor:

Length – If the material has actually a much longer length, this will an outchathamtownfc.nete in a higher number the collisions with other ions in ~ the conductor, raising the resistance and making it harder because that the current to flow.Cross-sectional area – With a big cross-sectional area, there is much less chance of collisions and also the resistance will decrease.Temperature – higher temperatures will result in an increased vibration of the ions, make the opportunities of electrons colliding greater and the resistance will certainly increase.

Ohm’s Law:

Ohm’s law describes the relationship in between current, voltage and also resistance:


= the voltage (in V)

= the present (in A)

= the resistance (in Ω).

Ohmic and non-ohmic resistors:

Ohmic conductors obey Ohm’s law and also have a consistent resistance. The resistance of non-ohmic conductors varies for different voltages. Irradiate bulbs are an example of a non-ohmic conductor. The resistance of irradiate bulb rises as the temperature the the filament increases.

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Ohmic and also non­-ohmic conductors deserve to be discover by plot a graph of existing vs voltage. The graph for an ohmic conductor is a straight line. The resistance have the right to be found from the gradient that the graph. The existing vs voltage graph for a non-ohmic conductor is not a directly line.


Example 1:

What voltage will circulation through a wire with a resistance of 1.5Ω to produce a current of 4A?




= 4A

= 1.5Ω


= 6V

Example 2:

What is the resistance that a wire the produces a present of 8A once a voltage that 2V is applied?