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05 November 2014. 6.5 Electrical Energy and Charge. How many meanings of the word charge can you think of?. 05 November 2014. 6.5 Electrical Energy and Charge. Page 192 AQA Physics. What is electric current? What is the unit of electric charge?
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05 November 2014 6.5 Electrical Energy and Charge How many meanings of the word charge can you think of?
05 November 2014 6.5 Electrical Energy and Charge Page 192 AQA Physics • What is electric current? • What is the unit of electric charge? • What energy changes take place when charge flows through a resistor?
What is electric current? Conventional current Conventional current electrons In metals current is a flow of electrons. In all materials current is a flow of charged particles.
What is the unit of charge? • Charge is measured in Coulombs, C. • Charge flow = current x time (Coulombs) (Amperes) (seconds) E.g. A flow of 2A for 5s is a charge of 10 Coulombs. Page 192 Q a) The capacity store of a battery is shown as Amp-hours or milliamp-hours (mAh). This tells you how long a battery can deliver a certain current.
Energy and potential difference Energy transformed = potential difference x charge flow From page 193 copy the worked example and answer b).
Summary • An electric current is a flow of charge. • When charge flows through a resistor, electrical energy is transferred as heat. • Charge = Current x time • Energy transferred = pd x time