Physics Form 4 Lessons Difficult to Learn, Difficult to Teach Lesson Concepts Floating and SinkingFloating and Sinking – JimmyCloud Chamber Radiation DetectorRadiation Characteristics Thermionic EmissionsHalf Wave RectificationFull Wave RectificationFull Wave Rectification 2Geiger Muller TubeDefects of Vision ElectromagnetismSemiconductorsPN SemiconductorsP-N JunctionsP-N Junctions-2Cathode Ray