GR9 ELECTRICITY & EFFECTS STUDENT VERSION by Lizelle Swanepoel https://padlet.com/lizellexs/52iwze841urukkwo en-us 2020-05-22 16:33:26 UTC 2025-11-02 03:21:24 UTC hello@padlet.com https://padlet-assets.s3.amazonaws.com/icons/Lightdecrease.png HOW TO WIRE A PLUG lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343567 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343567 What is electricity? lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343569 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343569 How is electricity produced? lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343570 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343570 Current, Voltage and Resistance lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343572 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343572 Series and parallel circuits lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343573 Calculations]]> 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343573 Ammeters and Voltmeters lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343575 An ammeter measures current in a circuit. 
  • An ammeter has VERY LITTLE RESISTANCE. 
  • An ammeter is always connected in SERIES with components in a circuit, as it must allow all the current to flow through it in order to measure current. 

A Voltmeter measures potential difference between two points in a circuit. 
  • A voltmeter has GREAT RESISTANCE. 
  • A Voltemeter must therefore always be connected in parallel with a component in a circuit, in order to measure the difference in potential energy between two points right before and after a resistor. 

]]> 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343575 Electrical conduction in metals lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343577 Metals consist of a “sea” of delocalised electrons surrounding positive ions. 
  • The delocalised electrons are free to move through the crystal structure. 
  • When metals are connected to a power source, the electrons all drift in the same direction which creates an electric current (flow of charge at a certain rate).
]]> 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343577 CURRENT lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343579 Current = The rate of flow of charge between two points in a circuit. ]]> 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343579 VOLTAGE lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343580 Voltage = Electrical energy transferred per unit charge between two points in a circuit. ]]> 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343580 RESISTANCE lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343581 Resistance = A material’s opposition to the flow of current through it.

The factors that affect resistance of a resistor: 
  • Length
  • Thickness
  • Temperature
  • Type of material (resistivity)

State the relationship between resistance and each of these factors, and give a reason for each relationship. 
]]> 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343581 OHM'S LAW lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343583 States: 
Current through a conductor is directly proportional to potential difference across a conductor, provided the temperature of the conductor stays constant. ]]> 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343583 lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343584 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343584 Solving circuit problems using Ohm’s Law (R=V/I) lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343585 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343585 lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343586 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343586 lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343588 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343588 Use the diagram to explain as many circuit concepts as you can: lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343590 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343590 LOOK OUT FOR MISCONCEPTIONS ABOUT SIMPLE CIRCUITS lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343592
Students sometimes fail to discriminate between these terms and concepts:

  • Potential difference (pd) versus voltage: 
  • pd - it emphasises that we are measuring a change in “push” between two different points in an electric circuit (rather than “push” at one point).

  • Electromotive force (emf) is a term for 'voltages' across sources of electrical energy.

  • Cells becoming 'discharged' - charge is not used up, energy is transferred.

  • Conventional current:
    - This flows (by definition) from positive to negative around the external circuit 
    - Inside the cell chemical reactions ‘pump’ charge carriers to the terminals. 
    - Some may say that ‘physicists got it wrong because we now know that electrons flow the other way.’ 
    - But it is really an arbitrary choice. 
    - One can illustrate this by looking at current flow and movement of charge carriers in an electrolyte (or an ionized gas). 
    - Positive ions go one way, negative ions go the other way. 
    - And so, however current is defined, there are always examples where current direction and charge carrier movement are opposite.

  • Current flows all around a circuit: including through the cell itself.

  • A useful analogy for charge flow:
    A Bicycle Chain!
    - This transfers energy from you (equivalent to the cell) to the rear wheel.
    - The chain is not used up (neither is charge),
    - and does not disappear when you run out of energy (when the cell runs flat and the chemical reactions within it stop).
    - It has no beginning and no end.
    - It moves as a SYSTEM, every part all at once.
    - this is the CYCLIC SIMULTANEOUS MODEL OF ELECTRIC CIRCUITS. 

  • Another analogy:
  • Skiers (charges) being lifted up a mountain by a ski lift (external energy source/emf/cell) and then skiing down a slope (resistor). 
  • This is useful for the idea of voltages in parallel circuits. 
  • Parallel slopes drop different skiers through the same vertical height (equal voltages across components in parallel).
]]> 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343592 CIRCUIT PROBLEM - EXAM STYLE lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343595 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343595 ELECTROMAGNETS lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343596 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343596 Uses of electromagnets lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343597 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343597 Indicate the following on the diagram below: lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343598
  • The direction of current flow in the coil around the iron nail.
  • The North pole and South pole induced in the right and left sides of the nail respectively.
    • ]]>     2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343598     Electromagnetism in action lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343599 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343599 Electromagnetism lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343601 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343601 lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343602 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343602 An electron gun (cathode ray tube) lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343605 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343605 CERN (European Organization for Nuclear Research) lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343607 The world’s largest application of electromagnets!!
    • Electromagnets are used to bend protons in a circular path close to the speed of light!
    ]]>     2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343607     Superconducting electromagnets in the LHC at CERN lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343608 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343608 Saints at CERN! lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343609 August 2019]]> 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343609 At CERN Control Centre lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343610 Spot Kyle Mlambo in the photo. 😎]]> 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343610 lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343611 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343611 CERN CONTROL CENTRE lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343613 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343613 “Going through the portal” and then descending 100m underground to CMS in the LHC. lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343614 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343614 100m underground at the CMS Detector in the Large Hadron Collider! lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343615 Spot Mr Mlambo in the front row!]]> 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343615 lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343617 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343617 lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343619 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343619 CERN VISITS lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343620 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343620 Geneva: home of CERN lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343621 Lake Geneva]]> 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343621 HANDS-ON AT CERN! Building Cloud Chambers in the S’COOL LAB lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343624 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343624 lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343625 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343625 Dry ice in action lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343626 Not “ice that is dry” ...]]> 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343626 The boys observing their cloud chambers in action lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343627 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343627 Mr Mlambo and team observing cosmic rays zipping through their cloud chamber lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343628 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343628 Cloud chamber in action! lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343629 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343629 lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343630 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343630 The CERN Globe lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343632 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343632 Armand in front of the CERN Globe statue! lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343633 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343633 All the clocks at CERN, in every room and office, are ROLEX. lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343635 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343635 Us on 1st ascent towards Mont Blanc! lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343637 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343637 The Magic of Electricity lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343643 The Eiffel lights start twinkling at 10pm every hour on the hour, for 5 minutes, till 1am. Beautiful!]]> 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343643 THE CHEMICAL EFFECT OF ELECTRICITY lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343644 Electrolysis]]> 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343644 Electrolysis - general explanation lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343646 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343646 GENERATION OF ELECTRICITY lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343647 Electricity is generated using generators in large power stations. It is then transmitted and distributed to homes and businesses via the National Grid.

    What is the National Grid?
    Def:
    The National Grid = A system or set of parts (such as power stations, transmission lines, transformers, buildings) which function together as a whole to generate and deliver electricity.]]>     2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343647     How a generator works lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343648 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343648 Transformers lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343649
  • A transformer is a device that transfers electrical energy from one electrical circuit to another through electromagnetic induction. Transformers are used to increase (step-up) or decrease (step-down) voltage in AC circuits.
    • How they work:
    ]]>     2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343649     Step-up vs. step-down transformers lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343652 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343652 EXTRA QUESTIONS lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343655 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343655 ELECTRICITY: A BRIEF HISTORY lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343663 TIMELINE]]> 2020-05-22 16:33:26 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589343663 NOTES lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/589370375 2020-05-22 16:47:44 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/589370375 lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/592851253 2020-05-25 12:26:43 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/592851253 lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/603366950 2020-05-31 15:09:06 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/603366950 lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/609859741 2020-06-03 21:51:31 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/609859741 lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/609859880 2020-06-03 21:51:39 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/609859880 lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/609859996 2020-06-03 21:51:47 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/609859996 lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/628617959 2020-06-16 09:06:51 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/628617959 lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/636523646 2020-06-22 19:03:27 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/636523646 lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/636560147 2020-06-22 19:39:45 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/636560147 COST EXERCISE lizellexs https://padlet.com/lizellexs/52iwze841urukkwo/wish/643088347 2020-06-29 15:39:38 UTC https://padlet.com/lizellexs/52iwze841urukkwo/wish/643088347