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Understand the concept of electric current, its relation to voltage, and the essential components for current flow. Includes videos and interactive resources.
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Electric current An introduction : https://www.youtube.com/watch?v=1xPjES-sHwg
Electric current Electric current is an ordered motion of charge carriers between two points having different electric potential ( = voltage) . In a metal wire the charge carriers are the conduction electrons, while in a liquid or in a gas theyare ions or , or by both ions and electrons such as in a plasma There are two fundamental quantities in electricity: current and voltage. Voltage is the cause and current is its effect.
We are goingtostudy the current in metals. The conventional direction of the current, for historical reasons, is defined as opposite to the direction of motion of the electrons. http://ed.ted.com/lessons/electric-vocabulary#watch
For an electric current to flow, we need two things: 1) something to make the charges flow, such as a battery , a device thatis able to maintain a constant voltage between two points (a potential electric difference ), as the water rushes down only if there is a different gravitational potential energy between two points at different height.
For an electric current to flow, we need two things: 2) a complete path for the current to flow in. This is called an electric circuit.
WHAT IS AN AMP https://www.youtube.com/watch?v=8gvJzrjwjds
How do we define the rate of current? Current is the numberofCoulombs thatpasses a point during a second. Wemeasureit in Amps. So ifthereis a currentof 5 A flowing , itmeansthat 5 C per second are passing a givenpoint.
WHAT IS VOLTAGE • https://www.youtube.com/watch?v=TBt-kxYfync
How do we define the voltage? Voltage is the potential difference between two points : it is the potential to do work . It is measured in Volt. So if there is a voltage of 5 V, it means that 1 C has the potential to do 5 J of work.
Part1 Charge and current : https://www.youtube.com/watch?v=KUMxSTgLSKM Part 2 Charge and current : https://www.youtube.com/watch?v=MluOUYm8rZA
A revision from BBC bitesize http://www.bbc.co.uk/bitesize/ks3/science/energy_electricity_forces/electric_current_voltage/activity/
A test from BBC Bitesize http://www.bbc.co.uk/bitesize/quiz/q74171589