中二物理......電阻+短路......10點

安培計既電阻要超級超級細,,

係因為安培計For串聯,,

串聯中若電阻太大,,

就會令電路電流太少,,

一來負載(燈泡)唔著,,

2來安培計既Magnet吾會轉,,

相反,,

伏特計既電阻要超級超級大,,

因伏特計For並聯,,

若並聯時電阻超級超級少,,

就會短路,,

Get吾到佢真實數據,,又破壞電路元件!

短路係2條帶有不同電位既任何導體,,

吾經任何負載或只經少阻抗(電阻)而接返電源,,

係一個電路,,

如果燈泡短路,,

短路既路徑電阻比燈泡既路徑為少,,

因為大量電流流去短路既路徑,,

而燈泡既路徑則少有電流(少到冇)

樓上位仁兄答得太深喇對中二同學黎講, 而且都只係copy一段野出黎..或者我簡單d解釋啦
1. 首先, 你要知道安培計 同埋 伏特計既接駁方法同作用
a.安培計 - in series(串聯), 伏特計 - parallel(並聯)
b.安培計 - 量度電流, 伏特計 - 量度電壓

當接駁安培計後, 由於佢既電阻(R)好細, 就會對整個電路影響減至最細, 就可以讀出準確的電流讀數

公式: V = I R

至於伏特計, 佢係並聯接駁, 當佢既電阻比需要量度的電路兩點大出很多, 經過佢既電流就會近乎零, 由以上公式可見, 佢比較返自己本身個 I (電流) 同埋 R (電阻), 就可以計算出準確的電壓數值, 因為用並聯接駁所量度的兩點, 電壓值是永遠一樣的

2. 短路的意思, 就係電路中帶電的其中兩點意外接觸了(例如: 一條電線內幾條線因為膠皮熔左而接觸了), 此舉會令整個電路不同了, 因為短路的地方, 電阻值會近乎零, 所以電流就會跟原有電路完全不同, 以燈泡為例, 電線在接駁燈泡前的位置已經接通左, 電流就唔會通向燈泡(因為燈泡-任何電器 有電阻), 而改為向短路的電線走了, 如果短路的地方係外間可接觸, 更會造成所謂漏電的情況

補充樓上師兄
係電路上
安培計 - in series(串聯) = 用來量電路上既電流
伏特計 - in parallel(並聯) = 用來量電源電壓
用電阻器連接儀表

安培計 + 電阻 = in parallel(並聯) 須讓大電流通過，電阻低可以減少電壓降。
伏特計 + 電阻 = in series(串聯) 須降低電流，電阻高可以阻止大電流通過。

1.點解安培計既電阻要超級超級細，而伏特計既電阻要超級超級大?
Ammeter (安培計) is an instrument to measure the current of a certain point in a circuit. As such, it has to connected in series with this point in order to let current flowing through it (ammeter). The ammeter therefore needs to be designed to have its resistance as low as possible in order not to alter the original current of the circuit.
A voltmeter (伏特計) is an instrument used to measure the voltage across two points in a circuit. As such, it needs to be connected to these two points. In so doing, current would be by-passed through the voltmeter, this would alter the original voltage. Hence, the voltmeter must be designed to have large resistance so as not to draw much current from the circuit.
2.what is短路?點解短路會令燈泡唔著?
Short-circuit (短路) is the by-passing of current through a low resistance path.
When a light bulb is made short-circuit, all current pass through the low resistant path (the short-circuit path), no current would pass through the bulb. Hence, it would not glow.