{
  "schemaVersion": "1.0",
  "id": "https://elect-learn.org/zh/lesson/04-voltage-current-power/",
  "url": "https://elect-learn.org/zh/lesson/04-voltage-current-power/",
  "markdownUrl": "https://elect-learn.org/zh/lesson/04-voltage-current-power/index.md",
  "jsonUrl": "https://elect-learn.org/zh/lesson/04-voltage-current-power/index.json",
  "language": "zh",
  "title": "电压、电流、电阻与功率",
  "description": "把常见公式变成直觉：电压推动，电流流动，电阻限制，功率变成热和做功。",
  "kind": "lesson",
  "safetyNotice": "学习参考：不同国家/地区的电气规范、许可和验收主体差异很大，本课程不替代当地法规、持证培训、现场许可或主管部门要求。任何实操前都应断电、验电，并遵守当地 AHJ/监管机构和雇主流程。",
  "sections": [
    {
      "id": "ohms-law-tool",
      "heading": "用两个已知量练习公式关系",
      "paragraphs": [
        "使用免费计算器完成理想直流电阻正数练习，再说明哪两个量是输入值、哪两个量由公式求得。"
      ],
      "links": [
        {
          "title": "打开欧姆定律计算器",
          "url": "https://elect-learn.org/zh/tools/ohms-law-calculator/"
        }
      ]
    },
    {
      "id": "section-1",
      "heading": "课程信息",
      "paragraphs": [
        "电路基础 · 基础 · 20 min",
        "电路",
        "交互演示"
      ]
    },
    {
      "id": "section-2",
      "heading": "电压推着走，电阻限制流，功率说明消耗。",
      "paragraphs": [
        "电源提供电压。开关闭合，形成完整回路，负载才有电流。"
      ],
      "items": [
        "电压固定时，电阻越大，电流越小。",
        "理想电阻负载：I = U ÷ R。",
        "功率 P = U × I；下面数值来自同一个模型。"
      ]
    },
    {
      "id": "section-3",
      "heading": "学习目标",
      "items": [
        "用 V=I×R 和 P=V×I 解释负载。",
        "理解为什么电流和发热直接相关。",
        "把万用表读数和回路状态联系起来。"
      ]
    },
    {
      "id": "section-4",
      "heading": "同一个插排上接太多取暖器",
      "paragraphs": [
        "冬天房间冷，两个取暖器和电脑都接在同一个插排上，插头发热。",
        "错误判断: 以为只要没跳闸就安全。",
        "停手边界: 发现发热、焦味或变色要立即停止使用并断电。",
        "推理路径: 计算总功率和电流，检查回路额定值、插排额定值和负载持续时间。",
        "复习: 常见考点：欧姆定律、功率、电流与导线/设备额定值。"
      ]
    },
    {
      "id": "section-5",
      "heading": "完整知识点",
      "items": [
        "电压像推动差，电流是实际流过负载的量。",
        "功率越大，单位时间转换的能量越多，发热风险越值得关注。",
        "负载不是抽象符号，它就是灯、加热器、电机或充电器。"
      ]
    },
    {
      "id": "tool-multimeter",
      "heading": "数字万用表",
      "paragraphs": [
        "测量电压、连续性和电阻，用来验证现象而不是猜测。",
        "误用与边界: 把表笔插错孔或量程选错，可能烧表或造成危险。"
      ]
    },
    {
      "id": "tool-cable",
      "heading": "NM 线缆/导线",
      "paragraphs": [
        "承载回路电流，颜色和标识帮助识别用途。",
        "误用与边界: 线规、护套、环境或颜色使用错误都可能违反规范。"
      ]
    },
    {
      "id": "section-8",
      "heading": "常见误区",
      "items": [
        "只看电压，不看负载电流。",
        "把插排当作增加回路容量的设备。",
        "忽略持续负载和散热环境。"
      ]
    },
    {
      "id": "section-9",
      "heading": "安全流程",
      "items": [
        "列出所有负载的瓦数或安培数。",
        "用 P=V×I 估算电流。",
        "与设备、插排和回路额定值比较；有发热就停用。"
      ],
      "ordered": true
    },
    {
      "id": "quiz-1",
      "heading": "120V 下 1500W 取暖器约多少电流？",
      "paragraphs": [
        "约 12.5A，因为 I=P/V=1500/120。"
      ]
    },
    {
      "id": "quiz-2",
      "heading": "插头发热时应该继续观察吗？",
      "paragraphs": [
        "不应继续使用。停止、断电并排查额定值、连接和负载。"
      ]
    },
    {
      "id": "section-12",
      "heading": "回头看",
      "links": [
        {
          "title": "复习第 3 课：电压测量是跨两点并联测量。",
          "url": "https://elect-learn.org/zh/lesson/03-multimeter-basics/"
        }
      ]
    }
  ],
  "dateModified": "2026-10-23",
  "publisher": {
    "name": "Elect Learn",
    "url": "https://elect-learn.org"
  },
  "review": {
    "status": "not-independently-reviewed",
    "statement": "尚无独立专业审校记录。参考来源不代表来源机构审校或认可本站。",
    "policyUrl": "https://elect-learn.org/zh/methodology/"
  }
}