旋轉式溫度計PHY - Ans.fyi 參考答案

旋轉式溫度計PHY

2012-09-13 3:52 am

細閱以下資料

旋轉式溫度計多是圓形，由兩種不同的金屬（如銅和鐵），做成複合金屬片。當室溫升高時，由於不同金屬都有不同的澎脹程度，複合金屬片便會向一個方向地捲曲，捲曲時便會將複合金屬片上的指針轉動，拉動指針，利用彎曲的程度決定溫度，加上溫度計上的溫標，便可以展示溫度。

問題:為何金屬澎脹時,會令複合金屬片向一個方向地捲曲?

(P.S try the question in simple words if you can.)

Tanks

回答 (1)

天同

2012-09-13 6:43 am

✔ 最佳答案

This is already given. It is because of the difference in expansion of each metal in the bi-metallic strip.

Copper expands more than iron for the same temperature rise. Because the two metal strips are welded firmly onto one another, the difference in expansion makes the strip to bend in a curvature, with copper on the outer circle (due to its longer length than that of iron after expansion) and iron on the inner circle.

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