Introduction Conductors are materials which allow the electrical currentto pass these materials included the likes of Gold, Copper and Aluminium.Insulators are the opposite conductors as they don’t let the electrical currentto pass Insulators include the likes of Ceramic, Rubber and Plastic.
In betweenConductors and Insulators lays Semiconductors which are usually solid chemicalelements which will allow the electrical current to get pass but under specificconditions otherwise the current will not get through, which makessemiconductors very good at controlling the electrical current.The differences between the electrical behaviour ofconductors and insulators are to do with their electronic structure. Inconductors, the atoms of the material have some loosely bounded electrons whichhelp the material let the electrical current through.
In solid metals atomsshare one or more electrons and some of the electrons are not bound anymore toa specific atom but they are shared between all atoms which makes them free tomove around. The movement of these electrons conduct the electrical current.On the other hand, in Insulators all the electrons aretightly bound to their atoms, none of the electrons are free to move aroundwhich prevents electrical current passing through. Insulators don’t have anyfree charged particles which do not let the current flow through. In semiconductors, most of the electrons are very tight totheir atoms just like insulators but few electrons are free to move aroundwhich can form a weak electric current.
Semiconductors can be adjusted withimpurities which can free more or less electrons to move around. Units used to measure Electric current ( I ) unit used was ampere ( A )Inductance ( L ) unit used was henry ( H )Frequency ( f ) unit used was hertz ( Hz )Power ( P ) and energy ( E ) units used were watt ( W ) forPower and joule ( J ) Difference between AC and DC voltages AC and DC are different types of voltage or current used forthe conduction and transmission of electrical energy. The main differencebetween AC and DC is the direction flow of electrical current. DC voltage isconstant and doesn’t change, the flow of the current is in one direction and ata constant level.
On the other hand, AC flows in two directions in a movingcycle. The flow of the voltage in one direction by going to its peak voltageand decreasing back to zero at which point the flow reverses directions andincreases back to its peak and goes back to zero to repeat the process.AC is very efficient at delivering electrical current overlong distances, because the average voltage is zero and the average loss isalso zero. On the other hand, the constant pressure of DC voltage provides highamounts of power as therefore is used in devices such as electrical motors. Theexceptional power makes it efficient for certain uses, for example its used incar starter motors.
Can work be negative?Work is a measurement of energy, and it might seem odd tosee work negative but work can be negative. Considering an objected beinglifted in the upward direction, the force of gravity is acting in the downwarddirection. The displacement of the object is in the upward direction and theangle between the object and the force is 180o the work done by the gravitational force onthe object is negative. A mass of 1000kg is dropped through a height of 16m in 22s.To find work done in this question first we need to find theForce which is F=ma1000 x 10 = 10,000 acceleration is this case is the gravity pulling the mass towards theground 10,000 x 16 = 160,000 Work = 160,000 J Power developed isPower = work/time160,000/22 = 7272.73Power = 7272.
73 W Household average energy consumption 1 lightbulb over 6hours, a 60-watts consumption will use 60 x 6 = 0.360 kWh and 60 watt x 6 hours x 60 min x 60 seconds = 60 watt x 21600secs = 1,296,000 J10 x 1296000 = 12,960,000 J1 tv over 4 hours, 100 watts consumption will use 100 x 4 =0.400 kWh 400 x 14400 = 5,760,000 J1 washing machine over 3 hours, 1000 watts consumption will use1000 x 3 = 3 kWh1000 x 10800 = 10,800,000 JThe total average for 90 daysLight bulbs = 12,960,000 x 90 = 1,166,400,000 J = 324 kWhTV = 5,760,000 x 90 = 518,400,000 J = 144 kWhWashing machine = 10,800,000 x 30 = 324,000,000 J = 90 kWhAverage total in Joules = 1,166,400,000 + 518,400,000 +324,000,000 = 2,008,800,000 J Average total in kWh = 324 + 144 + 90 = 558 kWhCost of electrical bill for 90 days whenits 20p/kWh = 558 x 0.20 = 111.
6 The cost of the electrical bill =£111.60 Practice SectionIntroduction to resistorsResistors are electronic components which have a specific,never-changing electrical resistance. The resistor’s resistance limits the flowof electrons through a circuit. Resistors are usually added to circuits wherethey complement active components. Commonly resistors are used to limitcurrent.
The electrical resistance of a resistor is measured in ohms.The symbol for an ohm is the Greek capital-omega: ?. The definition of 1? isthe resistance between two points where 1 volt 1V of applied potential energywill push 1 ampere 1A of current.There are two major categories in resistors and they arebased on whether they are fixed or variable. The fixed resistors are the mostused type of resistor, the values are determined during the design process ofthe circuit and the resistor itself should never need to be changed.
On theother hand, variable resistors are resistors which consist of a fixed resistorelement and a slider which taps onto the main resistor element, this gives theresistor three connections to the component and in this way the resistor isused as a potential divider if all three connections are used.ConclusionIn conclusion, the practical results were very close to the theoreticalresults and no results was outside the ±5% range even though 1 result wasclose but it was still in that range which made the practice successful. Beforethe practical I expected a few results to be on 220k? and more to be on 219K?and 221K? but after analysing the results its clear to see that most of the resistorended up below 220K? instead of above. The factors which could have affectedthe results was possibly taking the result too fast instead of letting it stabilisea little bit and not moving the resistor around which could have affected myresults and I would take that into consideration when I would repeat thisexperiment. References Article title: Conductors& InsulatorsWebsite title: Learnabout-electronics.orgURL: http://www.learnabout-electronics.org/Resistors/resistors_01.phpDate: 28th December 2017 Article title: Workand energyWebsite title: Physics.bu.eduURL: http://physics.bu.edu/~duffy/py105/Energy.htmlDate: 30th December 2017 Article title: Differencesbetween AC and DCWebsite title: Quora.comURL: https://www.quora.com/What-is-the-difference-between-AC-and-DC-currents