IS QUESTION

Question

2.在SERIES CIRCUIT,,,2 個BULB 的 VOLMETER READING 同AMMETER ＲＥＡＤＩＮＧ 係咪一樣??? 咁3 / 4個BULBS呢!?
3.在PARALLEL CIRCUIT, 1ST Branch 的BULB 同 2ND BRANCH的BULB ,,的VOLMETER READING 同AMMETER ＲＥＡＤＩＮＧ 係咪一樣???
咁如果有 2個BULBS係1 st和 2nd BRANCH 分別地.咁THEIR VOLMETER READING 同AMMETER ＲＥＡＤＩＮＧ 係咪一樣??? THEIR READING OF VOLMETER AND AMMETER IS LARGER /SMALLER THAN 1BULB IN EACH BRANCH????
In Q2/3, IF THEY ARE NOT THE　SAME,咁WHICH HAS LARGER/SMALLER READING OF VOLMETER AND AMMETER???

1. ELECTRICITY 係 FROM 正 極去 負 極,定負 去 正?!

VERY GD ANS FOR PHYSICALxxx
BUT CAN U ANS q1 electricity is from...................?

Answer 1

Q2.在SERIES CIRCUIT,,,2 個BULB 的 VOLMETER READING 同AMMETER ＲＥＡＤＩＮＧ 係咪一樣??? 咁3 / 4個BULBS呢!?

If the two bulbs are identical (i,e, of the same resistance), then the voltage across and the current passing through each of them are equal.

The same goes to 3 or 4 identical bulbs in series.

If the bulbs are NOT identical, the one with greatest resistance would share the highest voltage and the one with samllest resistance the lowest, but the current passing through them is equal.

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Q3.在PARALLEL CIRCUIT, 1ST Branch 的BULB 同 2ND BRANCH的BULB ,,的VOLMETER READING 同AMMETER ＲＥＡＤＩＮＧ 係咪一樣???

Again, if the bulbs are identical, both voltage and current are the same.

If the bulbs are not identical, the one with lowest resistance has the largest current passing through it, but the voltage across the two bulbs are still the same.

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咁如果有 2個BULBS係1 st和 2nd BRANCH 分別地.咁THEIR VOLMETER READING 同AMMETER ＲＥＡＤＩＮＧ 係咪一樣???

If the bulbs are all identical, their voltage and current are the same for each bulb.

THEIR READING OF VOLMETER AND AMMETER IS LARGER /SMALLER THAN 1BULB IN EACH BRANCH????

The voltage across each bulb in the two-bulb branch circuit is smaller than the voltage across the bulb in the one-bulb bracnch circuit, because of the sharing of voltage across the two bulbs in the two-bulb bracnch.

The current through each bulb in the two-bulb branch circuit is also smaller than the current through the bulb in the one-bulb branch circuit, because of the doubling of resistance in each branch in the two-bulb branch circuit.

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In Q2/3, IF THEY ARE NOT THE　SAME,咁WHICH HAS LARGER/SMALLER READING OF VOLMETER AND AMMETER???

This depends on the resistance of each bulb and how they are connected (in series or in parallel).

Basically, more bulbs connected in series will increase the total resistance and hence decrease the total current. On the other hand, more bulbs connected in parallel will lower the total resistance and increase the total current .

2006-12-17 13:44:43 補充：
The charge carriers in a metal conductor (e.g. copper) are electrons, which flows from points of lower potential (-ve pole) to points of higher potential ( ve pole)......(cont'd) .

2006-12-17 13:45:52 補充：
.....But in other substances, like some semiconductors (e.g. germanium) or elctrolyte, there are also positive charge carriers that are responsible for conducting electricity, and these carriers flow from high potential ( ve pole) to low potential (-ve pole).......

2006-12-17 13:47:00 補充：
....... Notwithstanding the above, conventional current always flows from high to low potential, i.e. from positive to -ve poles.