PHYSICS-current electricity
hi,各位親愛既朋版A__A!我想問insulator系咪唔比電子流過?咁當一個charged obect(當系+),放近系個insulator度,咁會吾會有induction出現,會吾有d電子系insulator accumulate系個object果邊,咁系咪永遠只有電子,proton唔動?,咁當個charged object同個insulator放埋一起,d電子會唔會由insulator jump去個object度而去neutalize,會吾會有earthing當有induction? insulator應該只係俾較少既電荷通過唔係冇 原帖由 screen 於 12-9-2008 18:19 發表 http://www.nakuz.com/bbs/images/common/back.gif
insulator應該只係俾較少既電荷通過
唔係冇
幾多係少??:o
回復 3# 的帖子
少過conductor[] 原帖由 screen 於 13-9-2008 15:31 發表 http://www.nakuz.com/bbs/images/common/back.gif少過conductor[]
咁即系點丫- -有冇人幫下我丫...徬徨同無助中....>< 少到可以當無.
會考生可以假設insulator是沒有free electrons,完完全全跟conductor劃清界線就可以.
insulator第2個名叫dielectric material,在AC電下,同埋符合某些條件,就會polarize,間接通電. Capacitor既原理好類似,不過佢係用electrolyte做polarization,所以唔駛太高壓就成事....而如果想佢直接黎,好似conductor咁呢,就要好高壓先得..此時就會dielectric breakdown,變成ions.....其實係破壞左佢...
proton唔會郁,只有electron會郁,但係electron走左就會留低個hole,movement of hole is opposite to that of electrons, 所以我地當holes係+ve charge. yr1既電子野,已經忘記得7788.....
關於insulator的conductivity,自己睇.
Physics of conduction in solids
Electrical insulation is the olamba of electrical conduction. Electronic band theory (a branch of physics) predicts that a charge will flow whenever there are states available into which the electrons in a material can be excited. This allows them to gain energy and thereby move through the conductor (usually a metal). If no such states are available, the material is an insulator.
Most (though not all, see Mott insulator) insulators are characterized by having a large band gap. This occurs because the "valence" band containing the highest energy electrons is full, and a large energy gap separates this band from the next band above it. There is always some voltage (called the breakdown voltage) that will give the electrons enough energy to be excited into this band. Once this voltage is exceeded, the material ceases being an insulator, and charge will begin to pass through it. However, it is usually accompanied by physical or chemical changes that permanently degrade the material's insulating properties.
Materials that lack electron conduction must also lack other mobile charges as well. For example, if a liquid or gas contains ions, then the ions can be made to flow as an electric current, and the material is a conductor. Electrolytes and plasmas contain ions and will act as conductors whether or not electron flow is involved.
[ 本帖最後由 【YU】 於 13-9-2008 19:42 編輯 ] 原帖由 【YU】 於 13-9-2008 19:34 發表 http://www.nakuz.com/bbs/images/common/back.gif
少到可以當無.
會考生可以假設insulator是沒有free electrons,完完全全跟conductor劃清界線就可以.
insulator第2個名叫dielectric material,在AC電下,同埋符合某些條件,就會polarize,間接通電. Capacitor既原理 ...
how abt高考生[] 原帖由 piyopiyo 於 13-9-2008 07:51 PM 發表 http://www1.nakuz.com/bbs/images/common/back.gif
how abt高考生[]
其實都可以
只係爺太老... 原帖由 【YU】 於 13-9-2008 19:34 發表 http://www.nakuz.com/bbs/images/common/back.gif
少到可以當無.
會考生可以假設insulator是沒有free electrons,完完全全跟conductor劃清界線就可以.
insulator第2個名叫dielectric material,在AC電下,同埋符合某些條件,就會polarize,間接通電. Capacitor既原理 ...
O..THX VERYMUCH[] 原帖由 Zend 於 13-9-2008 20:08 發表 http://www.nakuz.com/bbs/images/common/back.gif
其實都可以
只係爺太老... 你都是差不多了[]