An A. C. voltage of 2000 volts is applied between the winding and ground to test the integrity of the insulation between the winding and core iron.

在线圈绕组和地线上加上200 0伏交流电以测试线圈绕组和芯铁之间的绝缘的整体性能。

youdao

In theory, you need molten iron in the core to generate one, but Mercury is so small, its core should have long since solidified.

理论上，你需要核心里的熔化铁来产生它，但是水星很小，它的核心凝固还要很久。

youdao

But, unlike the cores of the inner planets, the Moon's core contains little or no iron, while the typical planet-forming materials were quite rich in iron.

但是，与内行星的核心不同，月球的核心几乎不含铁，而典型的行星形成物质则富含铁。

youdao

That suggests these rocks have been near a molten iron core.

BBC: A fleeting encounter with an 'inbetweener'

Unlike any other asteroid known today, Vesta has an iron core surrounded by layers of mantle rock and crust, similar to Earth and Mars, preliminary gravity and density measurements suggest.

WSJ: Asteroid Vesta Gets a Close Study

Japanese researchers say the basalt in NWA 011 suggests the body from which it did originate had a core of molten iron with an outer covering of silicon and aluminium that formed a basaltic crust.

BBC: Mercury meteorite puzzle