1. An electric lamp is rated ‘250V 100W’ and an immersion heater is rated ‘250V 2kW’.
(a) The filament is made of a metal with a much higher melting point than that of the element. State a reason of this. (2 marks)
Answer:
The filament would not be easily melted at high temperature. (1 mark)
The heater element will never rise above 100℃. (1 mark)
Question:
為何有此結論？「The heater element will never rise above 100℃.」
一條關於物理的簡單問題
2010-04-13 6:49 am
回答 (2)
2010-04-13 5:01 pm
✔ 最佳答案
The working temperature of the filament of a light bulb is of order of thousand degrees Celsius. The use of a heating element is for boiling water, of which the boiling point is at 100 degrees Celsius. Since water boils at around 100 degrees and rarely exceed this temperature, the material of the heating element doesn't have to stand a temperature much higher than the boiling point of water. 
2010-04-13 5:04 pm
I don't know why the answer can be 「The heater element will never rise above 100℃.」.
I think this statement means that even though the immersion heater is used to boil water, the heating element will never rise above 100℃ because the boiling point of water water is100℃.
I think this statement means that even though the immersion heater is used to boil water, the heating element will never rise above 100℃ because the boiling point of water water is100℃.
收錄日期: 2021-04-13 17:11:55
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https://hk.answers.yahoo.com/question/index?qid=20100412000051KK01733