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: Conventional '''Current''' flows from [[positive]] to [[negative]]. This is because [[electricity]] was discovered before [[scientist]]s knew about [[electron]]s.
: In a [[salt]] [[solution]] '''current''' is the flow of both [[positive]] and [[negative]] [[ion]]s.
==Key Stage 4==
===Meaning===
'''Electrical current''' is the [[rate]] of flow of [[Electrical Charge|charge]].
===About Electrical Current===
: '''Current''' is [[measure]]d using an [[Ammeter]].
: The [[SI Unit]]s of '''current''' are [[Amp|amperes]], which are also called [[amp]]s ([[A]]).
: A '''current''' in a [[wire]] is a flow of [[electron]]s which are [[negative]]ly [[Electrical Charge|charge]]d [[particle]]s.
: Conventional '''Current''' flows from [[positive]] to [[negative]]. This is because [[electricity]] was discovered before [[scientist]]s knew about [[electron]]s.
: In a [[salt]] [[solution]] '''current''' is the flow of both [[positive]] and [[negative]] [[ion]]s.
: In a [[Series Circuit|series circuit]] the '''current''' is the same everywhere in the [[circuit]].
: In a [[Parallel Circuit|parallel circuit]] the '''current''' splits at a [[junction]].
===Equation===
'''Current''' = (Charge)/(time)
<math>I=\frac{Q}{t}</math>
Where:
<math>I</math> = The '''electrical current'''
<math>Q</math> = The amount of [[Electrical Charge|charge]] flowing past a point.
<math>t</math> = The time taken for the [[Electrical Charge|charge]] to flow.
: This can give the definition "Current (I) is the (=) amount of [[Electrical Charge|charge]] flowing past a point (Q) per (÷) unit time (t).
===Example Calculations===
{| class="wikitable"
| style="height:20px; width:300px; text-align:center;" |A charge of 15 Coulombs passes through a point in a circuit ever 0.5 seconds. Calculate the current flowing past this point correct to two [[Significant Figures|significant figures]].
| style="height:20px; width:300px; text-align:center;" |A capacitor stores a charge of 10C. It discharges in 12ms. Calculate the current flowing out of the capacitor correct to two [[Significant Figures|significant figures]].
|-
| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities'''
Q = 15C
t = 0.5s
| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities'''
Q = 10C
t = 12ms = 12x10<sup>-3</sup>s
|-
| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers into the [[equation]] and [[Solve (Maths)|solve]].'''
<math>I=\frac{Q}{t}</math>
<math>I=\frac{15}{0.5}</math>
<math>I=30A</math>
| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers into the [[equation]] and [[Solve (Maths)|solve]].'''
<math>I=\frac{Q}{t}</math>
<math>I=\frac{10}{12 \times 10^{-3}}</math>
<math>I=833.3A</math>
<math>I\approx830A</math>
|}