# Shared Flashcard Set

## Details

Electric Circuits
N/A
19
Physics
05/07/2011

Term
 Charge
Definition
 Unit: Coulombs (C).1A=1 C per second.
Term
 Electric current
Definition
 The rate of flowing charges (electrons). Unit: Ampere (A).Current = charge/ time. I=1/t. 1A=1 C per second.
Term
 Electron in terms of coulombs, and Amps.
Definition
 On electron has 1.6x10-19 coulombs. therefore, 1A=1/(1.6x10^-19) = 6.25x1018 electrons. (C/second)
Term
 Definifion of Ampere
Definition
 Current needed in order to flow charge through two wires placed 1 meter apart in a vacuum in order to produce a magnetic force between the two.
Term
 Electrical Potential Difference (Unit, and definiton)
Definition
 measured in voltage, unit: volt(V). 1 volt = 1 Joules of energy. Definition: work done per unit charge in moving a charge from one point to the other. p.d is how much energy electrons loose through electrical appliance. (Caused by resistance)
Term
 Difference between: Electrical potential difference(V) & Potential energy difference(J)
Definition
 potential difference=potential energy difference(J)/ unit charge (c)
Term
 Work Done in terms of energy
Definition
 Energy difference=energy converted= work done
Term
 Equation for potential difference
Definition
 change in V= work done/ charge = W/q
Term
 Electronvolt
Definition
 Energy associated with an electron moving through a potential difference of one volt. Same energy as work done on or by the electron when the field is applied. W=change in V times q = 1.6x10-19 J. 1 electronvolt=1.6x10-19 joules.
Term
 Resistance definition, unit, equation.
Definition
 Measure a material's ability to allow current to flow. Measured in ohms. (symbol:Horse shoe) R=V/I. Ratio of the voltage across the material to the current flowing through the material.
Term
 Drift velocity
Definition
 The rate at which the charge flows is dependent on the velocity of the charges. The drift velocity of electrons in a conductor depends on the resistance of conductor: 1)the cross-sectional area of conductor 2)Length of conductor 3)material of conductor 4)temperature of conductor     Also, the potential difference across the conductor.
Term
 Resistivity(rho) equation of Resistance in relation to Resistivity
Definition
 measure of the resistance of a certain material. R= rho(resistivity, or Ohmm)L/area
Term
 Ohm's Law
Definition
 the current through a wire is proportional to the potential difference across it, provided the temperature is unchanged. Ohm states that Resistance is constant if current or potential difference increases, as long as the temperature stays the same. R=V/I
Term
 Ohmic and Non-Ohmic behaviour
Definition
 Conductor is Ohmic if it obeys Ohm's law. Lamp is Non-ohmic, as a large current flows through and increase temperature and thus increase resistance. The gradient of a I/V graph decreases.
Term
 Electrical Power
Definition
 Power= Work Done/ Time Work done = energy difference = Vq Power = Vq/t q=It Power=IV Unit:Watt
Term
 ElectroMotive Force (EMF)
Definition
 Source of electrical energy. The emf of a source is eual to the electrical energy produced per unit charge inside the source. Unit: volt. Simple: The emf of a source is the maximum possible voltage it can create.
Term
 Potential Dividerdefinition
Definition
 A circuit that is able to vary(divide) the potential difference. Usually done by changing the resistrance. The potential divider circuilt involves a rheostat. The resistance is varied by changing the length of the wire that the current passes through via the sliding terminal in the middle.
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