1. Preparation - Chapter 1.1

2. Participation - Assignment P.5 Q3, 4, 5

3. Presentation - Blackboard, Student's Work

4. Possession
   > Appliances are energy converter.

> Main sources of energy in HK - electrical energy

> Internal energy produced is a kind of waste

> Efficiency = Useful output / total input where useful output is the desired output of the appliance.

> Overall efficiency vs end-use efficiency

> Overall efficiency = product of all efficiency of all processes

1.2 Cooking without fire

1. Preparation - Chapter 1.2a, Chapter 1.2b

2. Participation - Assignment P.16 Q5-7 and P.31 Q18, 24, 28

3. Presentation - Blackboard, Student's Work

4. Possession
   > Electric hot plate - low resistance wire, joule heating effect, conduction and radiation

> Induction cooker - high frequency alternating current, electromagnetic induction, joule heating of bottom plate, ferromagnetic material cookware

> Microwave oven - 12 cm wavelength microwaves sets water molecules into vibration, flip twice per period, metal grid has small hole traps the wave, stationary wave forms so turntable is used (why?) 

5. > From microwave wavelength, we may find speed of light!

6. Possession
   > Compare different cookers

> end-use efficiency

> cost-effectiveness - capital cost and operating cost