Most deflection tubes work in a similar way. Electrons are evaporated off a hot cathode (negative). They are accelerated...

Teaching Guidance 14-16

In an electron gun, the metal plate is heated by a small filament wire connected to a low voltage. Some electrons (the...

Teaching Guidance 14-16

Electrons were discovered by J J Thomson in 1897 – although he called them ‘corpuscles’. His discovery was based on...

Teaching Guidance 14-16

The Millikan experiment is hugely important. Between 1910 and 1911 Robert Millikan used some clever ideas and careful...

Teaching Guidance 14-16

Millikan recorded the results for 175 drops. He used 58 of those to calculate a value for the charge on an electron, e , which...

Teaching Guidance 14-16

In an electron gun, electrons are boiled off the surface of a hot metal plate. They leave the plate with very small speeds...

Teaching Guidance 14-16

There are a number of different cathode ray tubes available to schools. They all use similar electron guns but have different...

Teaching Guidance 14-16