The hyperphysics guide to DC electrical circuits

reikiman's picture

Resistence: "The electrical resistance of a circuit component or device is defined as the ratio of the voltage applied to the electric current whichflows through it"

Electric Current: "Electric current is the rate of charge flow past a given point in an electric circuit, measured in Coulombs/second which is named Amperes."

Voltage: "Voltage is electric potential energy per unit charge, measured in joules per coulomb ( = volts). It is often referred to as "electric potential", which then must be distinguished from electric potential energy by noting that the "potential" is a "per-unit-charge" quantity."

Electric Field: "Electric field is defined as the electric force per unit charge. The direction of the field is taken to be the direction of the force it would exert on a positive test charge. The electric field is radially outward from a positive charge and radially in toward a negative point charge."

Batteries: "Batteries use a chemical reaction to do work on charge and produce a voltage between their output terminals. The basic element is called an electrochemical cell and makes use of an oxidation/reduction reaction. An electrochemical cell which produces an external current is called a voltaic cell. Voltages generated by such cells have historically been referred to as emf (electromotive force). "

Moving Coil Meters: "The design of a voltmeter, ammeter or ohmmeter begins with a current-sensitive element. Though most modern meters have solid state digital readouts, the physics is more readily demonstrated with a moving coil current detector called a galvanometer. "

Electromotive Force: "When a voltage is generated by a battery, or by the magnetic force according to Faraday's Law, this generated voltage has been traditionally called an "electromotive force" or emf. The emf represents energy per unit charge (voltage) which has been made available by the generating mechanism and is not a "force". The term emf is retained for historical reasons. It is useful to distinguish voltages which are generated from the voltage changes which occur in a circuit as a result of energy dissipation, e.g., in a resistor. "

before comments


frodus's picture

I've been going to Hyperphysics for YEARS... since somewhere around 98

It IS one of THE BEST most COMPREHENSIVE resources available for just about everything. It may not go into 100% detail, but it covers most science topics, from electricity to quantum theory to sound and light.

I love how everything is laid out with bubbles and trees... very easy to follow.

Great link reikiman


Travis Gintz
1986 Honda VFR Conversion

Who's online

There are currently 0 users online.

Who's new

  • Gordongadget
  • Cold Rider
  • Persival
  • boomingheight
  • janet

Support V is for Voltage