Câu 7: Quan sát hình bên và cho biết đây là sơ đồ cấu tạo của loại máy nào trong các loại máy sau: A. Máy phát điện xoay chiều có cuộn dây quay. B. Động cơ điện một chiều. C. Máy biến thế D. Máy phát điện xoay chiều có nam châm quay. Câu 8: Ở Việt Nam các máy phát điện trong lưới điện quốc gia có tần số A. 25HZ. B. 50HZ. C.75HZ. D.100HZ Câu 9: Bộ phận chính của bộ góp điện trong máy phát điện xoay chiều gồm A. hai bán khuyên và hai chổi quét. B. hai vành khuyên và hai chổi quét. C. chỉ có hai vành khuyên. D. một bán khuyên, một vành khuyên và hai chổi quét Mn trl dùm em với ạ em cảm ơn ạ

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