Đặt điện áp xoay chiều u = 400cos100πt (u tính bằng V, t tính bằng s) vào hai đầu đoạn mạch AB gồm điện trở R mắc nối tiếp với đoạn mạch Y. Cường độ dòng điện hiệu dụng qua mạch là 2A. Biết ở thời điểm t, điện áp tức thời hai đầu mạch AB có giá trị 400V, ở thời điểm t + 1/400 (s) cường độ dòng điện tức thời qua mạch là A và đang giảm. Công suất tiêu thụ của đoạn mạch AB gần đúng là ?         

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Một số câu hỏi khác có thể bạn quan tâm.

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• Choose the correct sentence which is built from the words and phrases given:

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• Choose the correct sentence which is built from the words and phrases given:

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• Choose the correct sentence which is built from the words and phrases given:

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• Choose the best answer for the following sentence:

  Teacher: “Please pay ___________ to my lectures! They are important for your exams.”