The resistance of any electrical device is defined by the expression, R=V/I, where V (volts) is the potential difference across the device and I (amps) is the electrical current flowing through it. When a current of one amp flows through a resistor...

Electric resistance is the opposition to the flow of current and results in the creation of heat. A material with very low resistance, such as copper, allows current to flow very easily and is called an electric conductor. A material that has high...

The electrical resistance of a wire or circuit is a way of measuring the resistance to the flow of an electrical current. A good electrical conductor, such as a copper wire, will have a very low resistance. Good insulators, such as rubber or glass...

A measure in an electric circuit of the ratio between the voltage and the ELECTRIC CURRENT. The unit of measurement is the...

Electrical resistance is a measure of the degree to which an object opposes an electric current through it. Its reciprocal quantity is electrical conductance measured in siemens. Assuming a uniform current density, an object's electrical resistance is a...

Analogous to controlling electric flow to lights by turning a dimmer switch, scientists at the University of North Carolina at Chapel Hill (UNC) and North Carolina State University (NC) have found that they can control the electrical resistance of carbon nanotubes by simply...

Two years after its adoption, the European Union's (EU) internal electricity market (IEM) directive-which aims to reduce prices through integration of EU national electricity markets-is taking hold. Most EU countries were obliged to open 26.48% of their electricity market to competition by last...

Strap on your PVC boots, hike up your nylon stockings. It's time to celebrate the 100th birthday of the world's first entirely synthetic material, one that revolutionized manufacturing, transportation, fashion and more.Plastic.An exhibition opening Wednesday at London's Science Museum looks to a future that includes...

Two European scientists won the 2007 Nobel Prize in physics on Tuesday for a discovery that lets computers, iPods and other digital devices store reams of data on ever-shrinking hard disks.France's Albert Fert and German Peter Gruenberg independently discovered a physical effect in 1988 that...

Electric circuits are designed to transfer just sufficient energy to operate the components in the circuit. The potential difference across the components (and the current through them), are carefully controlled by the resistance in each part of the circuit. The relationship between potential difference, current and resistance was discovered by a German physicist, George Ohm, in 1826.

An official GCSE style essay that uses the correct format for GCSE physics essays and covers all aspects of the pre-experiment notes (aim, background information, fair test, safety, and prediction), the experiment itself (diagram, method, and results), and the post-experiment notes (analysis and evaluation).

Details an experiment investigating the effect of length on the resistance of a wire. Provides a scientific explanation for resistance in a wire. Gives the results of the experiments and suggests methods to extend it.