Topic 5.1: Electric Potential Difference, Current and Resistance Flashcards Preview

IB SL Physics > Topic 5.1: Electric Potential Difference, Current and Resistance > Flashcards

Flashcards in Topic 5.1: Electric Potential Difference, Current and Resistance Deck (14)
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Define electric potential

o Electric Potential: the potential energy that each coulomb of positive charge would have if placed at that point in the field


Define electric potential difference

Electric Potential Difference (V): The work done per unit charge moving a positive test charge between two points in a circuit. V=W/Q measured in volts.


Define potential difference

 the potential difference or p.d. is the energy transferred when one coulomb of charge passes from one point to the other point


Where does a potential difference act?

o A potential difference acts across a component


Define volt

o Volt (1V): Unit of potential difference. One joule of electric potential energy is transferred to other forms when one coulomb flows between two points.


• 5.1.2: Determine the change in potential energy when a charge moves between two points at different potentials

o Energy transferred is equal to the amount of electric potential energy gained or to the amount of kinetic energy gained


Define electronvolt

o Electronvolt: Unit of energy. The energy required to move one electron through a PD of one volt. W (eV) = q (electron charges) x V (volts)
o 1 eV = 1.6 x 10-19 J


Define electric current

o Electric Current (I): The rate of flow of charge. Unit is the ampere. Conventional current flows from positive to negative
 electrons flow from negative to positive
 measured using an ammeter
• the ammeter is placed in the circuit so that the electrons pass through it
o therefore placed in a series circuit


Define current

o The current is defined in terms of the force per unit length between parallel current-carrying conductors


Define resistance

o Resistance (R): The ratio of potential difference across a conductor to current through the conductor.


Define the ohm

o The Ohm (1Ω): 1Ω = 1V/A


State Ohm's Law

o Ohm’s Law: The current through a conductor is directly proportional to the voltage across its ends if the temperature and other conditions are constant.


Define non-ohmic conductor

o Non-Ohmic Conductor: A conductor which does not obey Ohm’s Law so V is not proportional to I.


Define power

o Power (P): The rate of converting energy. Unit is watt (W) = 1J/S