phy 分唔清 - ,-"

小霞的fans

我唔知current,,charge同voltage既分別..
睇左定義都唔係太明..

同埋V=W/Q

V同W有咩分別!?2者都係ENERGY -00-
同埋呢..2V 姐係有2J既energy per charge !?
1V=1J OF ENERGY -,- ??而呢1J就係個W !?
呢度唔係太明 -00- ..
好亂=-= 謝謝解答/3\"

dolphin_ice

我唔知current,,charge同voltage既分別..
睇左定義都唔係太明..

同埋V=W/Q

V同W有咩分別!?2者都係ENERGY -00-
同埋呢..2V 姐係有2J既energy per charge !?
1V=1J OF ENERGY -,- ??而呢1J就係個W !?
呢度唔 ...
小霞的fans 發表於 2/10/2009 11:34 PM

                               
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可能譯成中文會較易明白

current 是電流, 即是電子的流動方向的相反方向 (the opposite direction of the flow of electrons) 為什麼相反方向就...應該A-level時才需知道

Voltage 是電壓 , 2個能量值中間的差別
Voltage 又叫 potential difference.

Niva

1個negative chagred 既rod 放係一張冇charge到既aluminium foil上面..
a negative induced charge on the top side of aluminium.a positive induced charge on the bottom side of aluminium.
negative chagred 既rod 放響neutral既aluminium foil上邊
會吸引左foil 入邊既positive charge去top side of aluminium foil
而negative charge會去左bottom side
紅字果度應該搞亂左
另外,因為d positive 同negative charge純粹係個position變左
所以個foil仍然係neutral

小霞的fans

V = W/Q

W = QV

W那個是Energy (我書是用E的) 單位為J

Q是charge 單位: coulomb

V是voltage/ electromotive force
It's defined as the energy transferred per unit charge passing through...

...
arararchchch 發表於 2/10/2009 04:12 AM

                               
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謝謝..我仲想問呢..
A Van de Graaff generator is earthed and a positively-charged metal rod is brought near the dome.What is the charge on the dome just before and after the rod touches the dome ?
可唔可以有詳細解釋..!?

同埋我想問..
1個negative chagred 既rod 放係一張冇charge到既aluminium foil上面..
a negative induced charge on the top side of aluminium.a positive induced charge on the bottom side of aluminium.
咁其實塊aluminium係neutral定negative charged!?

Ivanhy92

我唔知current,,charge同voltage既分別..
睇左定義都唔係太明..

同埋V=W/Q

V同W有咩分別!?2者都係ENERGY -00-
同埋呢..2V 姐係有2J既energy per charge !?
1V=1J OF ENERGY -,- ??而呢1J就係個W !?
呢度唔 ...
小霞的fans 發表於 2-10-2009 23:34

                               
登錄/註冊後可看大圖

V = W/Q

W = QV

W那個是Energy (我書是用E的) 單位為J

Q是charge 單位: coulomb

V是voltage/ electromotive force
It's defined as the energy transferred per unit charge passing through...

即係話,1V電壓定為 當1C既charge流過會放出1J energy (唔一定係heat)
3V電壓 : 當1C既charge流過會放出3J energy

當流過既charge一樣, Energy dissipated愈大, V就愈大