ELECTRODYNAMICS by Lizelle Swanepoel https://padlet.com/lizellexs/gpi4iybckxbe en-us 2019-06-25 08:33:39 UTC 2025-12-20 02:42:11 UTC hello@padlet.com https://padlet.net/icons/png/1f9f2.png lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/369237413 2019-06-26 07:48:34 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/369237413 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/369237453 2019-06-26 07:48:49 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/369237453 CURRENT-CARRYING CONDUCTOR PLACED IN 2ND MAGNET FIELD lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/369237554
  • Both magnetic fields interact. 
  • The magnetic field between the opposite poles and the magnetic field around the current-carrying conductor reinforce each other on one side of conductor 
  • and cancel each other on the other side.
  • A Lorentz force is created = the force acting on the ccc in a MF
    • ]]>     2019-06-26 07:49:32 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/369237554     ANSWERS: EX 2-3 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/369238218 2019-06-26 07:55:59 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/369238218 MAGNETIC FIELD STRENGTH (symbol B, unit Tesla) lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/370669853 DEF = magnetic flux density (B) is a representation of the magnitude and direction of the magnetic field.]]> 2019-07-09 19:56:25 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/370669853 FLUX lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/370674818 Flux = the amount of “something” (electric field, magnetic field) passing through a surface. 

    Total magnetic flux depends on:
    • Strength of the field
    • Size of the surface it passes through
    • Orientation of the surface

    For a loop of area (A) in the presence of a uniform magnetic flux density (B), the magnetic flux (Ф) passing through the loop is:
    • Ф = BA cos θ
      • where θ = angle between magnetic flux density (B) and the normal to the loop of area (A).
      • where B = the magnetic field strength (in Tesla)
      • where A = area of the coil loop
      • Unit for Ф = Wb (Weber)
    ]]>     2019-07-09 21:03:53 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/370674818     GENERATORS - PRINCIPLE OF WORKING lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/370712405 A generator is a device that converts Ek --> Eelectric. It is a motor in reverse.

    In a motor:
    • A current is passed through a coil in a magnetic field, causing a force and the coil MOVES. A motor works on the principle of the motor effect.

    In a generator: 
    • A coil is rotated through a magnetic field, CAUSING A CURRENT to flow in the coil as the wire cuts across the magnetic field. This causes a changing magnetic field. 
    • A generator works on the principle of electromagnetic induction.
    • Induction = the production of current in a conductor as it moves through a changing magnetic field.
    • Faraday's Law of Induction applies in generators, stating that:
    • if a wire is moved back and forth in a magnetic field, it cuts across the lines of magnetic flux. This magnetic field pushes on electrons in the metal. This movement of electrons is electrical flow.
    The strength of a generator or motor depends on:
    • "B" - Strength of the magnetic field (flux density of the magnet)
    • "I"  - Current flowing or generated in the coil
    • "ℓ" - Length of the conductor in the magnetic field
    • "θ" - Angle between the conductor and the fixed magnetic field
    • Use this formula for calculations: 
      • F = B x I x ℓ x sin θ    
      • Also: F = Bqv ; q=charge, v=speed of rotor
    ]]>     2019-07-10 05:56:05 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/370712405     MAGNETIC FIELDS CAN BE PRODUCED BY ELECTRIC CURRENTS lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/370715585 Magnetic fields are produced by electric currents, which can be currents in wires (or microscopic currents associated with electrons in atomic orbits).

    EFFECTS OF AN ELECTRIC CURRENT (I.E. MOVING CHARGE):
    • Heating
    • Magnetism
    In electrodynamics we study the magnetic effect resulting from current flowing in a wire.
    • When charge moves in a medium, it generates a magnetic field perpendicularly around that medium.
    • This is electromagnetism (Below is an electromagnet).
    ]]>     2019-07-10 06:42:02 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/370715585     MAXWELL'S RIGHT HAND GRIP RULE lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/370715812 The right hand rule is used to find the direction of the magnetic field lines around a current carrying conductor (CCC).]]> 2019-07-10 06:43:54 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/370715812 VIDEO ANIMATION - HOW A MOTOR WORKS lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/370716645 2019-07-10 06:51:46 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/370716645 MOTOR VS. GENERATOR lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/370717264 2019-07-10 06:57:54 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/370717264 ELECTROMAGNETIC INDUCTION lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/370717664 2019-07-10 07:02:07 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/370717664 FARADAY'S LAW OF INDUCTION lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/370717959 DEF:
    • Faraday's Law = The emf induced in a coil/conductor is directly proportional to the rate of change of magnetic flux linkage.

    • Flux linkage = The product of the number of turns on the coil and the flux through the coil (NФ)

    The electromotive force (Voltage) generated in a generator is given by Faraday's Law, below.

    Emf is affected by these factors:
    • Number of turns in the coil
    • Rate of change of flux 
    ]]>     2019-07-10 07:05:08 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/370717959     LENZ'S LAW lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/370718420 Def:
    Lenz's Law = The induced current in a coil/conductor flows in a direction so as to set up a magnetic field to oppose the change in the magnetic flux.

    The negative sign in Faraday's law is due to the fact that:
    • The emf induced in the coil acts to oppose any change in the magnetic flux.
    • Work is done to push the permanent magnet against the coil's induced magnetic field.
    • Energy is conserved (Emechanical --> Eelectrical).

    Lenz's Law:
    • gives the direction of an induced EMF which induces a current flow. 
    • the current flows in a direction to oppose the change (an increasing or decreasing magnetic field) causing it.
    ]]>     2019-07-10 07:11:02 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/370718420     IMPORTANT GENERATOR CONCEPTS lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/370720373 2019-07-10 07:37:54 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/370720373 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/370723009 2019-07-10 08:10:29 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/370723009 GENERATORS AND ELECTROMAGNETIC INDUCTION lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/370723267 2019-07-10 08:13:11 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/370723267 AC vs. DC GENERATOR lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/370724129 AC Generator = An ALTERNATOR
    DC Generator = A DYNAMO]]>     2019-07-10 08:23:06 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/370724129     AC GENERATOR lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/370724348 2019-07-10 08:26:25 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/370724348 THE COMPONENT OF THE MAGNETIC FIELD VECTOR PARALLEL TO THE NORMAL IS WHAT IS USED IN CALCULATIONS (Bcosθ) lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/370848064 2019-07-11 09:53:39 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/370848064 DRAW AND INTERPRET GRAPHS OF MAGNETIC FLUX LINKAGE VS. TIME lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/370849677 For an AC generator, indicating how:
    • the position of the NORMAL TO THE COIL relative to the magnetic field relates to the flux linkage magnitude.
    ]]>     2019-07-11 10:12:38 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/370849677     FACTORS AFFECTING EMF OF A GENERATOR lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/370854137 Factors affecting induced emf:
    • Position of the coil
      • If parallel to the external magnetic field (B), then flux lines are not 'cut' and zero induced emf is generated.
      • If perpendicular to an external magnetic field (B), then flux lines are being 'cut' and an induced emf is generated.
    • Strength of the magnetic field
    • Number of turns on the coil
    • Area of the coil
    • Coil wound around an iron core or not.
    • Rotation speed of the coil 
      • i.e. Rate of change in magnetic flux or rate with which coil "cuts" across the permanent magnetic field
    ]]>     2019-07-11 11:16:41 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/370854137     PARTS OF THE AC GENERATOR lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/370854689 ALTERNATOR]]> 2019-07-11 11:23:25 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/370854689 USES OF AC GENERATORS lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/370855321
  • Power plants have generators rotated by water or steam.
  • Car alternators charge battery when driving.
  • Diesel/petrol generators as alternative power supply when off-grid.
  • Moving coil microphones use alternators. 
    • Sound waves vibrate a membrane which move a coil in a magnetic field.
    • This induces a varying current which gets amplified and fed to a loudspeaker.
    • ]]>     2019-07-11 11:32:24 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/370855321     TRANSFORMERS lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/370856358 PURPOSE OF A TRANSFORMER = It is used to increase or decrease AC voltage.
    • The Number of turns on the primary and secondary coils affect the input and output voltages.
    What type of transformer is this?
    ]]>     2019-07-11 11:48:19 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/370856358     ANSWERS (Ex4 -10; p26-61) lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/372015971 2019-07-23 10:07:53 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/372015971 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/372016553 2019-07-23 10:17:55 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/372016553 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/372016554 2019-07-23 10:17:55 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/372016554 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/372016555 2019-07-23 10:17:55 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/372016555 The Diode & it’s function in rectification lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/372016685 2019-07-23 10:20:31 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/372016685 MAGNETISM lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/607574901 MAGNETIC FIELD = The region around a magnet where another magnetic material will experience a force.
    • Magnetic field direction is N to S outside the magnet.
    • Magnetic field direction is S to N inside the magnet.
    • Magnetic field lines representing the strength and direction of the magnetic field.
    • Magnetic field lines are continuous lines, forming closed loops.

    ONLY THREE METALS ON EARTH ARE NATURALLY MAGNETIC:
    • Fe, Co, Ni. (they are called ferromagnetic)

    ]]>     2020-06-02 19:30:53 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/607574901     lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/607598815 2020-06-02 19:47:02 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/607598815 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/607605658 2020-06-02 19:51:46 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/607605658 OR lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/607613800 2020-06-02 19:56:51 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/607613800 RIGHT HAND SOLENOID RULE lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/607621033 Curly fingers = points in direction of current in solenoid.
    Thumb = points to NORTH POLE generated by current in the solenoid.    ]]>     2020-06-02 20:01:46 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/607621033     THE MOTOR EFFECT lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/607625945 2020-06-02 20:05:09 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/607625945 FLEMING'S LEFT HAND RULE lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/607650307 2020-06-02 20:21:51 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/607650307 HAND RULES EXPLAINING INTERACTION BETWEEN CURRENTS AND MAGNETIC FIELDS lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/607668003
  • Right Hand Grip Rule
  • Fleming Left Hand Rule
    • ]]>     2020-06-02 20:34:48 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/607668003     MOTOR EFFECT HOMEWORK lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/607683956 2020-06-02 20:45:39 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/607683956 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/607704382 2020-06-02 21:01:13 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/607704382 WHAT PHENOMENON IS ILLUSTRATED BELOW? lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/607739016 Click to watch the video:]]> 2020-06-02 21:30:18 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/607739016 OUR STORY STARTS WITH HANS CHRISTIAAN OERSTED (DANISH PROFESSOR) lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/607754723 Hans Christiaan Oersted was a Danish Professor who discovered the link between electricity and magnetism. Watch the short video above:]]> 2020-06-02 21:43:37 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/607754723 MOTOR EFFECT HOMEWORK: ANSWERS lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/611583431 2020-06-04 17:33:11 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/611583431 THE DC MOTOR lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/612518707 2020-06-05 08:14:19 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/612518707 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/612523080 2020-06-05 08:17:32 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/612523080 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/612525485 2020-06-05 08:19:17 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/612525485 THE SPLIT RING COMMUTATOR FUNCTION lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/612526001 2020-06-05 08:19:39 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/612526001 FLEMING'S RIGHT HAND RULE lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/618191381 Use this hand rule to determine the direction of flow of CURRENT induced within the coil.]]> 2020-06-09 06:25:09 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/618191381 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/623120868 2020-06-11 20:37:03 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/623120868 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/623123188 2020-06-11 20:38:36 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/623123188 THE AC GENERATOR (ALTERNATOR) lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/623126434 2020-06-11 20:41:10 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/623126434 EXAM STYLE QUESTION lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/623142282 2020-06-11 20:54:41 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/623142282 ANSWERS lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/623145549 2020-06-11 20:57:44 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/623145549 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/623147358 2020-06-11 20:59:19 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/623147358 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/623151424 2020-06-11 21:03:21 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/623151424 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/623164377 2020-06-11 21:16:55 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/623164377 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/623174567 2020-06-11 21:27:47 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/623174567 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/623179247 2020-06-11 21:33:07 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/623179247 EM INDUCTION EXPLAINED lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/631573643 2020-06-18 05:10:08 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/631573643 WATCH THIS VIDEO lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/631576015 2020-06-18 05:12:43 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/631576015 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/635223273 2020-06-21 18:25:05 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/635223273 THE DIODE lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/635337014 An electronic component that allows electricity flow in one direction only. 
    • Like a sort of water VALVE. 
    • Signal diodes
    • Rectifier diodes
    ]]>     2020-06-21 21:18:06 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/635337014     AC WAVEFORM lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/635349251 Alternating current electrically alternates in polarity from a positive to a negative (and vice versa).
    • Our household power is generated as AC in power stations.
    • Most devices is not compatible with AC, but uses DC to operate. 
    ]]>     2020-06-21 21:40:34 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/635349251     lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/635351700 2020-06-21 21:44:37 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/635351700 FULL-WAVE RECTIFICATION lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/635353136 2020-06-21 21:47:19 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/635353136 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/635356241 2020-06-21 21:52:42 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/635356241 WHO INVENTED THE DIODE? lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/635358925 In 1909 he jointly received the Nobel Prize for his groundbreaking contributions to wireless radio and television.]]> 2020-06-21 21:58:20 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/635358925 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/635359113 2020-06-21 21:58:43 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/635359113 DEVICES USING DC TO OPERATE lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/635367935 2020-06-21 22:17:07 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/635367935 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/635369099 2020-06-21 22:19:45 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/635369099 HOW TO CHANGE AC TO DC? lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/635370126 2020-06-21 22:21:43 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/635370126 RECTIFICATION lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/635371662 Changing AC to DC - by aid of a bridge rectifier.]]> 2020-06-21 22:25:13 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/635371662 BRIDGE (DIODE) RECTIFIER IN A REAL CIRCUIT lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/635374979 2020-06-21 22:31:30 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/635374979 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/635377335 2020-06-21 22:36:35 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/635377335 CAPACITOR SMOOTHENS THE PULSATING DC CURVE lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/635378030 2020-06-21 22:38:15 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/635378030 LED BRIDGE RECTIFIER IN ACTION lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/635383297 2020-06-21 22:50:07 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/635383297 LED BRIDGE RECTIFIER ON A BREADBOARD lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/635384689 2020-06-21 22:52:00 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/635384689 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/635386400 2020-06-21 22:55:45 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/635386400 EXAM STYLE QUESTION ON RECTIFIERS lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/635387596 2020-06-21 22:58:36 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/635387596 HOMEWORK lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/635387869 EXERCISE 10]]> 2020-06-21 22:59:15 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/635387869 LED lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/635391695 2020-06-21 23:06:38 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/635391695 VIDEO lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/662314136 2020-07-25 10:04:57 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/662314136 ELECTROSTATIC VS GRAVITATIONAL FIELDS IN ACTION - BUILD YOUR OWN PARTICLE ACCELERATOR! lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/662318036 2020-07-25 10:30:19 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/662318036 WHAT WE WILL BE STUDYING IN THIS SECTION lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/663257307 1. MOTORS
    Energy conversion: Electrical energy 🡆 Kinetic energy]]>     2020-07-27 12:38:59 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/663257307     lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/663258200 2. GENERATORS
    Energy conversion: Kinetic energy 🡆 Electrical energy]]>     2020-07-27 12:40:26 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/663258200     lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/663262632 2020-07-27 12:48:32 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/663262632 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/663265972 2020-07-27 12:55:04 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/663265972 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/663266677 2020-07-27 12:56:19 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/663266677 TRANSFORMER EQUATIONS YOU NEED TO KNOW lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/663280187 2020-07-27 13:18:06 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/663280187 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/663282558 2020-07-27 13:21:40 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/663282558 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/663357051 2020-07-27 14:57:05 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/663357051 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/663357294 2020-07-27 14:57:24 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/663357294 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/663357522 2020-07-27 14:57:43 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/663357522 MOTORS - EXAM QUESTION lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/663368186 2020-07-27 15:12:05 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/663368186 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/663368673 2020-07-27 15:12:44 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/663368673 GENERATORS - EXAM QUESTIONS lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/663369018 2020-07-27 15:13:13 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/663369018 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/663369506 2020-07-27 15:13:58 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/663369506 lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/664029803 2020-07-28 09:45:07 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/664029803 THE MAGNETIC EFFECT OF CURRENT lizellexs https://padlet.com/lizellexs/gpi4iybckxbe/wish/664044273
  • Discovered by Hans Christiaan Oersted
  • This effect is called the electromagnetic effect
    • ]]>     2020-07-28 10:31:07 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/664044273     ELECTRODYNAMICS – TOPIC POINTERS https://padlet.com/lizellexs/gpi4iybckxbe/wish/1686278129 • Seeing that the laws and rules for generators and motors are similar, it is imperative to immediately, when starting with these questions, determine whether you are working with a generator or a motor, and one should also determine whether you are working with an alternating current (AC) or direct current (DC) device. 
     
    • Motors will always have an electrical power supply connected to them and generators will always have an electrical component connected to the device. 
     
    • The unfortunate news is that this section is often used for “out-of-the-box” type questions. These questions require a lot of insight and interpretation. Experience is key in widening your understanding of the intricate nature of these devices. DO AS MANY PAST PAPERS AS POSSIBLE!
     
    • Graphs – these are the most difficult graphs of them all. The signs (+ or -) and relative values of the tangent lines’ gradients of the given graphs are used to find the critical points on corresponding graphs. This will be explained using Faraday’s Law of Electromagnetic induction and the formula used in calculating induced emf: 
     
    The emf induced is directly proportional to the rate of change of magnetic flux (flux linkage). 
    𝜀=−𝑁Δ𝜙/Δ𝑡 
     
    From the two points mentioned above it can be derived that when one is given a magnetic flux (flux linkage) vs time graph the negative of the gradient at any given point on the graph (the gradient of the tangent line at that point) would be equal to the induced emf at that specific time. Take note that the graphs of emf vs time and magnetic flux (flux linkage) vs time is out of phase. The graphs of emf vs time and current vs time is in phase with one another. 
    • The inner workings of a transformer are very important, and it should be described in the following way: 
     
    Alternating current enters the primary coil. 

    This leads to a change in the magnetic field around the primary coil as the direction of the input current is periodically changing. 

    Because of this there will be a change in the magnetic flux through the secondary coil. 

    This then leads to an emf being induced in the secondary coil. 

    An alternating current will then be induced in the secondary coil according to Ohm’s Law (V=IR). 
     
    • We will only work with ideal transformers. These are transformers where no loss of power occur. 𝑃𝑖𝑛=𝑃𝑜𝑢𝑡. 
    ]]>     2021-08-19 15:53:49 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/1686278129     PAST EXAM PAPER QUESTIONS ON ELECTRODYNAMICS https://padlet.com/lizellexs/gpi4iybckxbe/wish/1686284706 2021-08-19 15:57:28 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/1686284706 https://padlet.com/lizellexs/gpi4iybckxbe/wish/1686286825 2021-08-19 15:58:38 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/1686286825 https://padlet.com/lizellexs/gpi4iybckxbe/wish/1696804668 2021-08-25 20:39:21 UTC https://padlet.com/lizellexs/gpi4iybckxbe/wish/1696804668