2007 年
物理 · 共 41 題 · 點擊選項即時核對答案
只看錯題本頁已答 0 / 1
41.
| Specification : | |
|---|---|
| Voltage input | V |
| Voltage outputs | V & V |
The above figure shows a portable transformer. It outputs different voltage by varying the turns ratio between the primary and the secondary coils. Assume that there is no power loss in the transformer and the resistance of the load remains unchanged, when the output changes from V to V, which of the following statements describing the transformer is/are correct ?
(1)The number of turns of the primary coil should be doubled and the number of turns of the secondary coil remains unchanged.
(2)The input current should be doubled.
(3)The output power should be times as before.