Wednesday, 25 September 2019

Term 4 Week 1 2019

Exam Revision NCEA Level 3 Physics Exam Revision

Wave Systems | NCEA Level 3 Physics | StudyTime NZ



Mechanical Systems | NCEA Level 3 Physics | StudyTime NZ


Electrical Systems | NCEA Level 3 Physics | StudyTime NZ



Monday, 23 September 2019

Term 3 Week 10 2019

Homework

  • Ex 6A, p.251-254 Level 2 D.C. Circuit Revision
  • Ex 6B, p.261-261 Internal Resistance of a Battery
  • Ex 6C, p.267-272 Kirchhoff's Laws
  • Ex 6D, p.277-280 Capacitors Ep = ½ QV
  • Ex 6E, p.283-284 Capacitors C = 𝜺r𝜺oA/d
  • Ex 6F, p.289-292 Capacitor Networks (Series & Parallel)
  • Ex 6G, p.298-300 Capacitor Charge & Discharge
  • Ex 6H, p.303-305 Inductance in D.C. Circuits
  • Ex 6I, p.308-310 Inductors Charge & Discharge
  • Ex 6J, p.311-312 Transformers
  • Ex 6K, p.314-315 A.C. Peak and r.m.s.
  • Ex 6L, p.316-317 A.C. Capacitor Reactance
  • Ex 6M, p.319-320 A.C. Inductor Reactance
  • Ex 6N, 321-324 A.C. RCL Impedance



  • RCL Phase Relationships





    Impedance of a Capacitor Resistor Circuit
    Z = √(XC2 + R2)
    θ = tan-1(-XC/R) = tan-1(-VC/VR)
    The Capacitor Reactance is 90° behind the Resistance
    The Capacitor Voltage is 90° behind the Resistor Voltage


    Impedance of a Inductor Resistor Circuit
    Z = √(XL2 + R2)
    θ = tan-1(XL/R) = tan-1(VL/VR)
    The Inductor Reactance is 90° ahead of the Resistance
    The Inductor Voltage is 90° ahead of the Resistor Voltage


    Impedance of a RCL Circuit
    Z = √((XL - XC)2+ R2)
    θ = tan-1((XL - XC)/R) = tan-1((VL - VC)/VR)

    Resonance



    A.C. Circuits & Resonance

    MIT Physics Demo -- Resonant RLC Circuit


    Monday, 16 September 2019

    Term 3 Week 7 2019

    Homework
  • Ex 6A, p.251-254 Level 2 D.C. Circuit Revision
  • Ex 6B, p.261-261 Internal Resistance of a Battery
  • Ex 6C, p.267-272 Kirchhoff's Laws
  • Ex 6D, p.277-280 Capacitors Ep = ½ QV
  • Ex 6E, p.283-284 Capacitors C = 𝜺r𝜺oA/d
  • Ex 6F, p.289-292 Capacitor Networks (Series & Parallel)
  • Ex 6G, p.298-300 Capacitor Charge & Discharge
  • Ex 6H, p.303-305 Inductance in D.C. Circuits
  • Ex 6I, p.308-310 Inductors Charge & Discharge
  • Ex 6J, p.311-312 Transformers

  • Right Hand Screw Rule


    Right Hand Slap Rule

    Magnetic Flux







    Lenz's Law

    Faraday;'s Law & Lenz's Law
    Inductance






    Transformers


    The ratio of the secondary to primary voltage is equal to the ratio of the secondary to primary turns

    Vs/Vp = Ns/Np

    In an Ideal Transforme
    Secondary Power = Primary Power
    In reality, energy is lost through heat from eddy currents generated in the soft iron core from the changing flux.

    NB: As Voltage is often referred to as e.m.f. the Symbol "e" or "E" is often used in engineering to refer to e.m.f.
    This is the case in the video below.
    After explaining how basic Transformers work, this video goes on to explain 3-Phase Transformers.

    NZ Street Step-Down Transformer

    Internal Diagram of a Transformer

    Faraday Cage


    Tesla Coil & Faraday Cage



    Exploding Cans with Electromagnets

    Levitating with Electromagnets

    Sunday, 18 August 2019

    Term 3 Week 3 2019

    Homework
  • Ex 6A, p.251-254 Level 2 D.C. Circuit Revision
  • Ex 6B, p.261-261 Internal Resistance of a Battery
  • Ex 6C, p.267-272 Kirchhoff's Laws
  • Ex 6D, p.277-280 Capacitors Ep = ½ QV
  • Ex 6E, p.283-284 Capacitors C = 𝜺r𝜺oA/d
  • Ex 6F, p.289-292 Capacitor Networks (Series & Parallel)
  • Ex 6G, p.298-300 Capacitor Charge & Discharge

  • Capacitor
    C = Q/V


    Capacitors
    Basic Definition
    Physical Parameters
    Energy Stored
    Ep = ½ QV


    Capacitors & Capacitance


    Dielectric
    An insulating material placed in between the capacitor plates to increase the Capacitance

    C = 𝜺r𝜺oA/d





    Dielectrics in Capacitors


    Capacitor Circuits


    Capacitors in Series
    Calculating Voltage Charge and Total Capacitance

    Capacitors in Parallel
    Calculating Voltage Charge and Total Capacitance


    Capacitors in Parallel vs Capacitors in Series


    Capacitors in Combination
    Series & Parallel Capacitors

    Capacitors in Combination
    Patrallel & Series Capacitors

    Capacitors in Series
    Calculating Voltage Drop


    Capacitors in Series
    Calculating the Charge Stored

    Capacitors in Series
    Calculating the Equivalent Capacitance


    Capacitors in Parallel
    Calculating Voltage Drop

    Capacitors in Parallel
    Calculating the Charge Stored


    Capacitors in Parallel
    Calculating the Equivalent Capacitance


    Capacitor Charge & Discharge


    RC Circuits 1: Charging and Discharging a Capacitor