Week 4 Term 3 2022

  Homework:

• Act 13A, p.205-206 Level 2 D.C. Circuit Revision
• Act 13B, p.210-211 Battery Internal Resistance
• Act 13C, p.214-216 Kirchhoff's Laws
• 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
• Act 14A, p.240 Capacitance & Capacitors
• Act 14B, p.244-245 Capacitor Networks & Energy
• Act 14C, p.249-251 Charging & Discharging Capacitors
• Ex 6D, p.277-280 Capacitor Energy
• Ex 6E, p.283-284 Capacitors
• Ex 6F, p.289-292 Capacitor Networks
• Ex 6G, p.298-300 Charging & Discharging Capacitors
• Act 15A, p.259-260 Induced Voltage & Current
• Act 15B, p.263-264 Transformers
• Act 15C, p.268-269 Inductance
• Act 15D, p.272-273 Voltage and Current Graphs for the Inductor
• Ex 6H, p.303-305 Inducatnace in DC Circuits
• Ex 6I, 308-310 Inductance: Self; Mutual; Time Constant; Energy Stored
• Ex 6J, p.311-312 Transformers

Capacitor

C = Q/V

Capacitors

Basic Definition

Physical Parameters

Energy Stored

Ep = ½ QV

Capacitors & Capacitance

Capacitors Explained

Dielectric

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

C = 𝜺r𝜺oA/d

Dielectrics in Capacitors

PhET Capacitor Lab Basics - App

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

Right Hand Screw Rule

Right Hand Slap Rule

Magnetic Flux

Faraday's Law - PhET Application

Lenz's Law

Faraday's Law & Lenz's Law

Inductance

Inductor PhET Demonstration

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 Transformer 

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

How Do Substations Work?

Fuse MCB, How it Works