Term
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Definition
Unit: Coulombs (C).
1A=1 C per second. |
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Term
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Definition
The rate of flowing charges (electrons). Unit: Ampere (A).
Current = charge/ time. I=1/t.
1A=1 C per second. |
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Term
Electron in terms of coulombs, and Amps. |
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Definition
| On electron has 1.6x10-19 coulombs. therefore, 1A=1/(1.6x10^-19) = 6.25x1018 electrons. (C/second) |
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Term
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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. |
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Term
Electrical Potential Difference
(Unit, and definiton) |
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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) |
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Term
Difference between:
Electrical potential difference(V)
&
Potential energy difference(J) |
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Definition
| potential difference=potential energy difference(J)/ unit charge (c) |
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Term
Work Done
in terms of energy |
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Definition
| Energy difference=energy converted= work done |
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Term
Equation for potential difference |
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Definition
change in V= work done/ charge = W/q |
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Term
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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. |
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Term
Resistance
definition, unit, equation. |
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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. |
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Term
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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. |
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Term
Resistivity(rho)
equation of Resistance in relation to Resistivity |
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Definition
measure of the resistance of a certain material.
R= rho(resistivity, or Ohmm)L/area |
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Term
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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 |
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Term
| Ohmic and Non-Ohmic behaviour |
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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. |
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Term
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Definition
Power= Work Done/ Time
Work done = energy difference = Vq
Power = Vq/t
q=It
Power=IV
Unit:Watt |
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Term
| ElectroMotive Force (EMF) |
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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. |
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Term
Potential Divider
definition |
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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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