9_4_1

**1. Increased understandings of cathode rays led to the development of television** §  explain why the apparent inconsistent behaviour of cathode rays caused debate as to whether they were charged particles or electromagnetic waves worksheet - 'cathode rays: A historical perspective' Read and Complete table for information relating to particles or waves. §  perform an investigation and gather first-hand information to observe the occurrence of different striation patterns for different pressures in discharge tubes Jacaranda HSC Science - Physics 2 Prac 10.1

§  perform an investigation to demonstrate and identify properties of cathode rays using discharge tubes: § – containing a maltese cross § – containing electric plates § – with a fluorescent display screen § – containing a glass wheel – analyse the information gathered to determine the sign of the charge on cathode rays http://staging.cli.nsw.edu.au/physics/ §  explain that cathode ray tubes allowed the manipulation of a stream of charged particles §  identify that moving charged particles in a magnetic field experience a force §  describe quantitatively the force acting on a charge moving through a magnetic field (F = q v B sin q)      §   identify that charged plates produce an electric field §  discuss qualitatively the electric field strength due to a point charge, positive and negative charges and oppositely charged parallel plates §  describe quantitatively the electric field due to oppositely charged parallel plates §  solve problem and analyse information using: (F = q v B sin q), F = qE and E = V/d Shadwick surfing Ideas book

§  outline Thomson’s experiment to measure the charge/mass ratio of an electron Textbook - Use resources to descibe: - what did Thomson want to do? - How did Thomson carry out his investigations? - What did Thomson eventually find? http://www.hscphysics.edu.au/resource/template.swf

§  outline the role of: § – electrodes in the electron gun § – the deflection plates or coils § – the fluorescent screen in the cathode ray tube of conventional TV displays and oscilloscopes Textbook - summarise how each works including diagrams