RESISTANCE Is Futile

“RESISTANCE is futile” (7 of 9 Star Treck Voyager)

Which road allows cars to move more easily?

Which pipe would be easier to crawl through?

Electrical Resistance is like this. Conductors allow electrons to move through them. The ease at which the electrons can move depends on:

 The material the conductor is made of - gold is the best conductor

 The length of the conductor

 The diameter of the conductor  The temperature of the conductor – cold conductors allow electricity to flow easier than hot.

The energy that is used to push a coulomb of charge through a light bulb filament depends on the resistance of the filament.

Electrical resistance is defined as: the ratio of potential difference across the load (V) to the current through the load (I)

R is used to represent resistance and is measured in units called OHMS (Ω)

R = V resistance = potential difference I current

The OHM is honour of Sir Georg Simon Ohm (1789 – 1854). Ohm was the first person to publish the results of his experiments on resistance. His observations are now called Ohm’s Law. The mathematical formula for this law is:

V = IR - Ohm’s Law

Any resistor that has a constant resistance is known as an Ohmic resistor.