Learning Objectives

--state that a current is a rate of flow of charge measured in amperes

--distinguish between conventional current and electron flow

--recall and apply the relationship charge = current x time time i.e. * Q = It = ne to new situations or to solve related problems

-- define electromotive force (e.m.f.) as the work done by a source in driving a unit charge around a complete circuit

-- calculate the total e.m.f. where several sources are arranged in series

--state that the e.m.f. of a source and the potential difference across a circuit component is measured in volts

--define the p.d. across a component in a circuit as the work done to drive a unit charge through the component

--*distinguish between e.m.f. and p.d. in terms of energy considerations

--*recall and solve problems using the equation V = W/Q

-- define resistance of a component as the ratio of potential difference across it to the current flowing through it

-- apply the relationship R= V/I to new situations or to solve related problems

--describe an experiment to determine resistance using a voltmeter and an ammeter and make the necessary calculations

-- recall and apply the formulae for the effective resistance of a number of resistors in series and in parallel to new situations or to solve related problems

--recall and apply the relationship of the proportionality between resistance and length and the cross-sectional area of a wire to new situations or to solve related problems

--state Ohm’s law

--describe the effect of temperature increase on the resistance of a metallic conductor

--sketch and interpret the V-I characteristic graph for metallic conductor at constant temperature, a filament lamp and for a semiconductor diode

-- show an understanding of the use of a diode as a rectifier


What is current electricity? What is the connection of this to all the charges in the topic on electrostatics?

Electric Current




Electric Potential Difference




Explore the follow simulation to understand the factors that affect the resistance of a resisitor.




Activity on resistance http://www.bbc.co.uk/scotland/learning/bitesize/standard/physics/using_electricity/resistance_activity.shtml

Ohm's law

Colour codes for resistors

More indepth explanation on current, resistance and power (For those who will be interested)


Alternating current