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

1

## 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

2

## 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.

3

## 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

4

## Where does a potential difference act?

### o A potential difference acts across a component

5

## 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.

6

## • 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

7

## 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

8

## 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

9

## Define current

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

10

## Define resistance

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

11

## Define the ohm

### o The Ohm (1Ω): 1Ω = 1V/A

12

## 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.

13

## Define non-ohmic conductor

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

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