The danger of electric shock is particularly high in bathrooms. Normal electric socket outletsshould not be installed in bathrooms. As electric shavers and toothbrushes are becomingpopular these days, a special unit, called ‘shaver supply unit’ is now common in bathrooms toprovide electricity just for these low power consumption electric appliances (Figure 9.1).The shaver supply unit consists of a transformer in which the secondary is not earthed and iscompletely isolated from the 220 V a.c. mains supply connecting to the primary. It can be usedwith 220 V or 110 V shavers.
上面可以唔洗睇
左primary circuit 右shaver circui
t
(b) Explain what would happen if the human body touches(i) the live wire of the mains supply in the primary circuit;
呢題我明啦....因為live 220v 人0v 有pd 然後d current pass through 人 再接地
(ii) one of the conducting wires in the shaver circuit outlet.呢題我唔明.......明明
shaver circuit
個voltage step down左
應該會同上小分題的答案一樣,.......但點解marking話 the circuit in the secondary circuit has no return path/complete circuit
唔係同人組成左個complete 接地的circuit咩.........
chem答埋單
點解esterification d ester可以用separating funnel 分開出來ge?
以like dissolve like 來講 alcohol/carboxylic acid/ester都係polar
然後都dissolve係同一隻solvent度
咁點separate??em46
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本帖最後由 aa764258 於 2014-2-10 12:46 AM 編輯 ]