Changes

An '''electrical current''' is a flow of [[Electrical Charge|charge]].

: The [[SI Unit|units]] 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 Charge|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 Charge|positive]] to and [[Negative Charge|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 negatively [[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 Charge|positive]] and [[Negative Charge|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=======Equation Linking Current, Charge and Time====''NB: You should remember this equation with charge as the subject of the formula.'' '''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)." ====Equation Linking Current, Potential Difference and Resistance====''NB: You should remember this equation.'' '''Current''' = (Potential Difference)/(Resistance) <math>I=\frac{V}{R}</math> Where <math>I</math> = The '''electrical current''' <math>V</math> = The [[Potential Difference|potential difference]] across a [[Electrical Component|component]]. <math>R</math> = The [[Electrical Resistance|resistance]] of an [[Electrical Component|component]]. ===Example Calculations=======Finding Current from Charge and Time===={| class="wikitable"| style="height:20px; width:300px; text-align:center;" |A charge of 15 Coulombs passes through a point in a circuit ever 0.52 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 in correct [[unit]]s.''' Q = 15C t = 0.52s| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities in correct [[unit]]s.''' Q = 10C t = 12ms = 12x10^-3s|-| 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}{0.52}</math> <math>I=28.846153A</math> <math>I\approx29A</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>|} ====Finding Charge from Current and Time===={| class="wikitable"| style="height:20px; width: 300px; text-align:center;" |A battery supplies 4.7Amps to a bulb over a period of 14 seconds. Calculate the charge leaving the battery in this time correct to two [[Significant Figures|significant figures]].| style="height:20px; width: 300px; text-align:center;" |A hairdryer uses a current of 7.2A for 5 minutes to dry a person’s hair. Calculate the charge flowing through the hairdryer in this time correct to two [[Significant Figures|significant figures]].|-| style="height:20px; width: 300px; text-align:left;" |'''1. State the known quantities in correct [[unit]]s.''' I = 4.7A t = 14s| style="height:20px; width: 300px; text-align:left;" |'''1. State the known quantities in correct [[unit]]s.''' I = 7.2A t = 5min = 300s|-| style="height:20px; width: 300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].''' <math>I=\frac{Q}{t}</math> <math>4.7=\frac{Q}{14}</math> | style="height:20px; width: 300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].''' <math>I=\frac{Q}{t}</math> <math>7.2=\frac{Q}{300}</math> |-| style="height:20px; width: 300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].''' <math>Q=4.7 \times 14</math> <math>Q = 65.8C</math> <math>Q \approx 66C</math>| style="height:20px; width: 300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].''' <math>Q=7.2 \times 300</math> <math>Q = 2160C</math> <math>Q \approx 2200C</math>|} ====Finding Time from Current and Charge===={| class="wikitable"| style="height:20px; width: 300px; text-align:center;" |A battery charger uses a current of 150mA to deliver a charge of 245 Coloumbs to a battery. Calculate the time taken to charge this battery correct to two [[Significant Figures|significant figures]].| style="height:20px; width: 300px; text-align:center;" |A cloud in a thunderstorm loses 15C in one lightening strike. At a current of 31,000kA. Calculate how long this lightning strike lasts correct to two [[Significant Figures|significant figures]].|-| style="height:20px; width: 300px; text-align:left;" |'''1. State the known quantities in correct [[unit]]s.''' I = 150mA = 150x10^-3A Q = 245C| style="height:20px; width: 300px; text-align:left;" |'''1. State the known quantities in correct [[unit]]s.''' I = 31,000kA = 3.1x10⁷A Q = 15C|-| style="height:20px; width: 300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].''' <math>I=\frac{Q}{t}</math> <math>150 \times 10^{-3} = \frac{245}{t}</math> | style="height:20px; width: 300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].''' <math>I=\frac{Q}{t}</math> <math>3.1 \times 10^7 = \frac{15}{t}</math>|-| style="height:20px; width: 300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].''' <math>t=\frac{245}{150 \times 10^{-3}}</math> <math>t=1633.3s</math> <math>t\approx1633.3s</math>| style="height:20px; width: 300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].''' <math>t=\frac{15}{3.1 \times 10^7}</math> <math>t = 4.8387 \times 10^{-7}s</math> <math>t\approx4.8 \times 10^{-7}s</math>|} ====Finding Current from Potential Difference and Resistance===={| class="wikitable"| style="height:20px; width:300px; text-align:center;" |A [[Potential Difference|potential difference]] of 9.9V is placed across an 19 Ohm [[Electrical Resistor|resistor]]. Calculate the '''current''' flowing through the [[Electrical Resistor|resistor]] correct to two [[Significant Figures|significant figures]].| style="height:20px; width:300px; text-align:center;" |A toaster has a [[Electrical Resistance|resistance]] of 27 Ohms is plugged into the [[Mains Electricity|mains]] which has a [[Potential Difference|potential difference]] of 230V. Calculate the current flowing through the toaster correct to two [[Significant Figures|significant figures]].|-| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities in correct [[unit]]s.''' V = 9.9V R = 19Ω| style="height:20px; width:300px; text-align:left;" |'''1. State the known quantities in correct [[unit]]s.'''V = 230V R = 27Ω|-| style="height:20px; width:300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers into the [[equation]] and [[Solve (Maths)|solve]].''' <math>I=\frac{V}{R}</math> <math>I=\frac{9.9}{19}</math> <math>I=0.52105A</math> <math>I\approx0.52A</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{V}{R}</math> <math>I=\frac{230}{27}</math> <math>I=8.519A</math> <math>I\approx8.5A</math>|} ====Finding Resistance from Potential Difference and Current===={| class="wikitable"| style="height:20px; width: 300px; text-align:center;" |A student measures a [[Potential Difference|potential difference]] of 5.4V and a current of 0.13mA across a component. Calculate the [[Electrical Resistance|resistance]] of the [[Electrical Component|component]].| style="height:20px; width: 300px; text-align:center;" |Calculating the [[Electrical Resistance|resistance]] of a [[buzzer]] connected in series to a 9V battery with an [[ammeter]] reading of 23mA.|-| style="height:20px; width: 300px; text-align:left;" |'''1. State the known quantities in correct [[unit]]s.''' V = 5.4V I = 0.13mA = 0.13x10^-3| style="height:20px; width: 300px; text-align:left;" |'''1. State the known quantities in correct [[unit]]s.'''V = 9V I = 23mA = 23x10^-3|-| style="height:20px; width: 300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].''' <math>I=\frac{V}{R}</math> <math>0.13 \times 10^{-3}=\frac{5.4}{R}</math> | style="height:20px; width: 300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].''' <math>23 \times 10^{-3}=\frac{9}{R}</math>|-| style="height:20px; width: 300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].''' <math>R=\frac{5.4}{0.13 \times 10^{-3}}</math> <math>R=41538.46\Omega</math> <math>R\approx 42000\Omega</math> | style="height:20px; width: 300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].''' <math>R=\frac{9}{23 \times 10^{-3}}</math> <math>R=391.3043\Omega</math> <math>R\approx 390\Omega</math>|} ====Finding Potential Difference from Current and Resistance===={| class="wikitable"| style="height:20px; width: 300px; text-align:center;" |A '''current''' of 55mA flows through a [[Electrical Component|component]] with a [[Electrical Resistance|resistance]] of 93 Ohms. Calculate the [[Potential Difference|potential difference]] across this [[Electrical Component|component]] correct to two [[Significant Figures|significant figures]].| style="height:20px; width: 300px; text-align:center;" |A 22kΩ [[Electrical Resistor|resistor]] has a '''current''' flowing through it of 6mA. Calculate the [[Potential Difference|potential difference]] across the [[Electrical Resistor|resistor]] correct to two [[Significant Figures|significant figures]].|-| style="height:20px; width: 300px; text-align:left;" |'''1. State the known quantities in correct [[unit]]s.''' I = 55mA = 55x10^-3A R = 93Ω| style="height:20px; width: 300px; text-align:left;" |'''1. State the known quantities in correct [[unit]]s.''' I = 6mA = 6x10^-3A R = 22kΩ = 22x10³Ω|-| style="height:20px; width: 300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].''' <math>I=\frac{V}{R}</math> <math>55 \times 10^{-3}=\frac{V}{93}</math>| style="height:20px; width: 300px; text-align:left;" |'''2. [[Substitute (Maths)|Substitute]] the numbers and [[Evaluate (Maths)|evaluate]].''' <math>I=\frac{V}{R}</math> <math>6 \times 10^{-3}=\frac{V}{22 \times 10^3}</math>|-| style="height:20px; width: 300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].''' <math>V= 55 \times 10^{-3} \times 93</math> <math>V= 5.115V</math> <math>V\approx5.1V</math> | style="height:20px; width: 300px; text-align:left;" |'''3. [[Rearrange (Maths)|Rearrange]] the equation and [[Solve (Maths)|solve]].''' <math>V= 6 \times 10^{-3} \times 22 \times 10^3</math> <math>V= 132V</math> <math>V\approx130V</math>|}  ===References=======AQA==== :[https://www.amazon.co.uk/gp/product/1782945598/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945598&linkCode=as2&tag=nrjc-21&linkId=ad276ad49df77ab4b40ab4fd0fe09817 ''Current (electrical), pages 180, 181, 190, GCSE Combined Science; The Revision Guide, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/178294558X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=178294558X&linkCode=as2&tag=nrjc-21&linkId=f0dfb66dafcb0c6e9449e7b1a4ae1ac76 ''Current (electrical), pages 24, 33, GCSE Physics; The Revision Guide, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945598/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945598&linkCode=as2&tag=nrjc-21&linkId=ad276ad49df77ab4b40ab4fd0fe09818 ''Current (electrical); alternating, page 188, GCSE Combined Science; The Revision Guide, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/178294558X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=178294558X&linkCode=as2&tag=nrjc-21&linkId=f0dfb66dafcb0c6e9449e7b1a4ae1ac77 ''Current (electrical); alternating, pages 31, 96, 97, GCSE Physics; The Revision Guide, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945598/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945598&linkCode=as2&tag=nrjc-21&linkId=ad276ad49df77ab4b40ab4fd0fe09819 ''Current (electrical); direct, page 188, GCSE Combined Science; The Revision Guide, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/178294558X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=178294558X&linkCode=as2&tag=nrjc-21&linkId=f0dfb66dafcb0c6e9449e7b1a4ae1ac78 ''Current (electrical); direct, pages 31, 97, GCSE Physics; The Revision Guide, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945598/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945598&linkCode=as2&tag=nrjc-21&linkId=ad276ad49df77ab4b40ab4fd0fe09820 ''Current (electrical); energy transferred, page 190, GCSE Combined Science; The Revision Guide, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945598/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945598&linkCode=as2&tag=nrjc-21&linkId=ad276ad49df77ab4b40ab4fd0fe09821 ''Current (electrical); I-V characteristics, page 183, GCSE Combined Science; The Revision Guide, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/178294558X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=178294558X&linkCode=as2&tag=nrjc-21&linkId=f0dfb66dafcb0c6e9449e7b1a4ae1ac79 ''Current (electrical); I-V characteristics, page 26, GCSE Physics; The Revision Guide, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945598/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945598&linkCode=as2&tag=nrjc-21&linkId=ad276ad49df77ab4b40ab4fd0fe09823 ''Current (electrical); magnetic field around a current-carrying wire, page 230, GCSE Combined Science; The Revision Guide, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/178294558X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=178294558X&linkCode=as2&tag=nrjc-21&linkId=f0dfb66dafcb0c6e9449e7b1a4ae1ac80 ''Current (electrical); magnetic field around a current-carrying wire, pages 93, 94, GCSE Physics; The Revision Guide, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945598/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945598&linkCode=as2&tag=nrjc-21&linkId=ad276ad49df77ab4b40ab4fd0fe09822 ''Current (electrical); mains supply, page 188, GCSE Combined Science; The Revision Guide, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945598/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945598&linkCode=as2&tag=nrjc-21&linkId=ad276ad49df77ab4b40ab4fd0fe09824 ''Current (electrical); national grid, page 191, GCSE Combined Science; The Revision Guide, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945598/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945598&linkCode=as2&tag=nrjc-21&linkId=ad276ad49df77ab4b40ab4fd0fe09825 ''Current (electrical); parallel circuits, pages 186-187, GCSE Combined Science; The Revision Guide, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945598/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945598&linkCode=as2&tag=nrjc-21&linkId=ad276ad49df77ab4b40ab4fd0fe09826 ''Current (electrical); series circuits, pages 185-187, GCSE Combined Science; The Revision Guide, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/0008158770/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=0008158770&linkCode=as2&tag=nrjc-21&linkId=ec31595e720e1529e49876c3866fff6e ''Current, pages 46-7, 52-69, 72-5, 247-9, GCSE Physics; Student Book, Collins, AQA '']:[https://www.amazon.co.uk/gp/product/019835939X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=019835939X&linkCode=as2&tag=nrjc-21&linkId=57e96876985fc39b1a3d8a3e3dc238b6 ''Current, pages 52-53, 58-61, 64-65, 68-71, 216-229, GCSE Physics; Third Edition, Oxford University Press, AQA '']:[https://www.amazon.co.uk/gp/product/1782946403/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782946403&linkCode=as2&tag=nrjc-21&linkId=32a0abb60dff015b15b50e9b1d7b4644 ''Current, pages 61-67, GCSE Combined Science Trilogy; Physics, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945970/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945970&linkCode=as2&tag=nrjc-21&linkId=a120d24dcc7cc7a58192069a3aafc1d2 ''Current, pages 63-69, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782946403/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782946403&linkCode=as2&tag=nrjc-21&linkId=32a0abb60dff015b15b50e9b1d7b4644 ''Current; alternating (ac), pages 86, 203, GCSE Combined Science Trilogy; Physics, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945970/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945970&linkCode=as2&tag=nrjc-21&linkId=a120d24dcc7cc7a58192069a3aafc1d2 ''Current; alternating (ac), pages 89, 245, 306, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782946403/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782946403&linkCode=as2&tag=nrjc-21&linkId=32a0abb60dff015b15b50e9b1d7b4644 ''Current; direct (dc), page 86, GCSE Combined Science Trilogy; Physics, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945970/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945970&linkCode=as2&tag=nrjc-21&linkId=a120d24dcc7cc7a58192069a3aafc1d2 ''Current; direct (dc), pages 89, 306, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782946403/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782946403&linkCode=as2&tag=nrjc-21&linkId=32a0abb60dff015b15b50e9b1d7b4644 ''Current; in parallel, pages 73, 74, GCSE Combined Science Trilogy; Physics, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945970/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945970&linkCode=as2&tag=nrjc-21&linkId=a120d24dcc7cc7a58192069a3aafc1d2 ''Current; in parallel, pages 75, 76, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782946403/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782946403&linkCode=as2&tag=nrjc-21&linkId=32a0abb60dff015b15b50e9b1d7b4644 ''Current; in series, page 69, GCSE Combined Science Trilogy; Physics, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945970/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945970&linkCode=as2&tag=nrjc-21&linkId=a120d24dcc7cc7a58192069a3aafc1d2 ''Current; in series, page 71, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945970/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945970&linkCode=as2&tag=nrjc-21&linkId=a120d24dcc7cc7a58192069a3aafc1d2 ''Current; induced, pages 303, 304, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945970/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945970&linkCode=as2&tag=nrjc-21&linkId=a120d24dcc7cc7a58192069a3aafc1d2 ''Current; magnetic field around a current carrying wire, pages 291, 292, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782946403/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782946403&linkCode=as2&tag=nrjc-21&linkId=32a0abb60dff015b15b50e9b1d7b4644 ''Current; magnetic field around a current-carrying wire, pages 218, 219, GCSE Combined Science Trilogy; Physics, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782946403/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782946403&linkCode=as2&tag=nrjc-21&linkId=32a0abb60dff015b15b50e9b1d7b4644 ''Current; measuring, pages 235, 236, GCSE Combined Science Trilogy; Physics, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1782945970/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1782945970&linkCode=as2&tag=nrjc-21&linkId=a120d24dcc7cc7a58192069a3aafc1d2 ''Current; measuring, pages 331, 332, GCSE Physics; The Complete 9-1 Course for AQA, CGP, AQA '']:[https://www.amazon.co.uk/gp/product/1471851370/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851370&linkCode=as2&tag=nrjc-21&linkId=01c69b0ae058f809cf636033e6ba793e ''Current-potential difference (I-V characteristic) graphs, pages 43-5, GCSE Physics, Hodder, AQA '']:[https://www.amazon.co.uk/gp/product/1471851354/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851354&linkCode=as2&tag=nrjc-21&linkId=9012a0d354024419214fb3ad5ac44ba0 ''Current-potential difference (I-V) graphs, pages 298-9, GCSE Combined Science Trilogy 1, Hodder, AQA '']:[https://www.amazon.co.uk/gp/product/1471851354/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=1471851354&linkCode=as2&tag=nrjc-21&linkId=9012a0d354024419214fb3ad5ac44ba0 ''Current-potential difference (I-V) graphs; investigating the characteristics of a circuit component, page 300, GCSE Combined Science Trilogy 1, Hodder, AQA '']:[https://www.amazon.co.uk/gp/product/019835939X/ref=as_li_tl?ie=UTF8&camp=1634&creative=6738&creativeASIN=019835939X&linkCode=as2&tag=nrjc-21&linkId=57e96876985fc39b1a3d8a3e3dc238b6 ''Current-potential difference graphs, page 55, GCSE Physics; Third Edition, Oxford University Press, AQA '']