(20點)氣體放電管與陰極射線

1.為什麼哥爾特斯坦的實驗要在低壓下進行？大氣壓力下不行嗎？高壓下不行嗎？
High gas pressure means the number of gas molecules per unit volume is large. Under such situation, energy of emitted electrons (which are constituents fo cathode rays) are readily absorbed by these gas molecules through continuous collisions, and are unable to reach the anode.


2. 為什麼要用高電壓？低電壓不行嗎？
As explained above, low voltage provides less energy to the emitted electrons. Such energy may not be sufficient for the electrons to reach the anode of the tube, forming a continuous current.


3. 從何見得電子是「高速」運行？
The velocity of electron can be calculated from the observed deflection under a known strength of electric or magnetic fields using classical electrodynamics theories.

1)氣在加壓1.73倍後令空氣粒子的排列更緊密,有助於實驗,
2)空氣一般定義為絕緣體,但高壓令空氣導電,產生電弧(Arc),
亦即陰極射線(Cathode-Ray),
此情況為擊穿,此高電壓為擊穿電壓!
3)吾悉,sorry.