Drift Velocity And Resistance
Drift velocity and resistance cheat sheet
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Drift velocity:
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The average velocity of charge carriers under an applied electric field.
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SI unit: meters per second (m/s)
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Mobility:
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The drift velocity per unit electric field strength
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SI unit: square meter per volt-second (m2/Vs)
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Resistivity:
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Resistance of a conductor of unit length and unit cross-sectional area.
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SI unit: ohm-meter (Ωm)
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Ohm’s law:
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The current through a conductor is directly proportional to the voltage across it and inversely proportional to its resistance.
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SI units:
- Current: Ampere (A)
- Voltage: Volt (V)
- Resistance: Ohm (Ω)
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Temperature dependence of resistivity:
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Metals: resistivity increases with temperature.
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Semiconductors: resistivity decreases with temperature.
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Superconductivity:
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Zero electrical resistance at a characteristic temperature (critical temperature).
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Requires cooling below the critical temperature.
