Advanced

Tutor model

i62 💰:9.4

i52 💰:7.9

🏆 i67 💰:62.5

i70 💰:125.0

i68 💰:125.0

🏆 i66 💰:75.0

i65 💰:125.0

i63 💰:62.5

i61 💰:75.0

i60 💰:9.4

i60 💰:37.5

i58 💰:62.5

i57 💰:22.5

i57 💰:37.5

i56 💰:45.0

⚡ i55 💰:11.25

i55 💰:37.5

i54 💰:62.5

i52 💰:35.0

i51 💰:37.5

i49 💰:15.0

i49 💰:62.5

i48 💰:11.3

i47 💰:7.5

i44 💰:25.0

i43 💰:37.5

i42 💰:187.5

i40 💰:5.0

i39 💰:100.0

i38 💰:37.5

i37 💰:11.0

i36 💰:187.5

i34 💰:12.5

i33 💰:37.5

i30 💰:1.0

i29 💰:1.5

i28 💰:150.0

i23 💰:20.0

i20 💰:4.0

i18 💰:1.0

i16 💰:25.0

i13 💰:1.5

Keep session private

What would you like to learn?

Override for the tutor's lesson content generation calls. Auto uses the system default (Claude Sonnet 5 for lesson text, Opus 5 for diagrams).

Lesson generation model

System default

i58 💰:18.8

i31 💰:11.0

i25 💰:31.3

Tutoring abilities

Imagine a sudden storm knocks out the power in your house. The kitchen stove and microwave shut off completely, but your flashlight clicks right on!

Why do some electric devices stop working the second the power cuts out, while others keep running without any problem?

Appliances that need huge amounts of energy plug into a wall outlet to use **mains electricity**.

This powerful electrical current travels through long underground and overhead cables all the way from distant power stations directly into your home.

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta name="aspect-ratio" content="4:3">
<title>Mains vs Battery Electricity</title>
<style>
  * {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    -webkit-tap-highlight-color: transparent;
  }

  body {
    background: #f8fafc;
    color: #1e2945;
    padding: 12px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 100%;
  }

  .nav-toggle {
    display: flex;
    background: #e2e8f0;
    padding: 3px;
    border-radius: 24px;
    gap: 4px;
    margin-bottom: 12px;
  }

  .toggle-btn {
    border: none;
    background: transparent;
    padding: 6px 16px;
    font-size: 14px;
    font-weight: 600;
    color: #64748b;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.25s ease;
  }

  .toggle-btn.active {
    background: #ffffff;
    color: #0ea5e9;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.08);
  }

  .view-container {
    width: 100%;
    max-width: 480px;
    position: relative;
    min-height: 280px;
  }

  .panel {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
    display: flex;
    flex-direction: column;
    gap: 10px;
  }

  .panel.active {
    opacity: 1;
    pointer-events: auto;
    position: relative;
  }

  .flow-card {
    background: #ffffff;
    border-radius: 16px;
    padding: 14px 10px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
    border: 1px solid #f1f5f9;
    display: flex;
    align-items: center;
    justify-content: space-around;
  }

  .flow-node {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    text-align: center;
  }

  .node-icon {
    font-size: 28px;
    line-height: 1;
  }

  .node-label {
    font-size: 11px;
    font-weight: 700;
    color: #64748b;
    text-transform: uppercase;
    letter-spacing: 0.5px;
  }

  .flow-arrow {
    color: #0ea5e9;
    font-weight: bold;
    font-size: 16px;
    animation: flowPulse 1.8s infinite ease-in-out;
  }

  @keyframes flowPulse {
    0%, 100% { transform: translateX(0); opacity: 0.4; }
    50% { transform: translateX(3px); opacity: 1; }
  }

  .props-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
  }

  .prop-chip {
    background: #ffffff;
    border-radius: 12px;
    padding: 8px;
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 12px;
    font-weight: 600;
    border: 1px solid #f1f5f9;
    box-shadow: 0 1px 4px rgba(0,0,0,0.02);
  }

  .prop-chip span:first-child {
    font-size: 18px;
  }

  .appliances-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
  }

  .appliance-item {
    background: #ffffff;
    border: 1px solid #e2e8f0;
    border-radius: 14px;
    padding: 10px 4px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    font-size: 12px;
    font-weight: 600;
    color: #1e2945;
  }

  .appliance-icon {
    font-size: 26px;
  }

  .status-badge {
    font-size: 10px;
    font-weight: 700;
    padding: 2px 6px;
    border-radius: 10px;
    margin-top: 2px;
  }

  .mains-badge {
    background: #e0f2fe;
    color: #0284c7;
  }

  .battery-badge {
    background: #fef3c7;
    color: #d97706;
  }
</style>
</head>
<body>

  <div class="nav-toggle">
    <button class="toggle-btn active" id="btn-mains" onclick="switchMode('mains')">🔌 Mains Power</button>
    <button class="toggle-btn" id="btn-battery" onclick="switchMode('battery')">🔋 Battery Power</button>
  </div>

  <div class="view-container">
    
    <div class="panel active" id="panel-mains">
      <div class="flow-card">
        <div class="flow-node">
          <span class="node-icon">🏭</span>
          <span class="node-label">Plant</span>
        </div>
        <span class="flow-arrow">➔</span>
        <div class="flow-node">
          <span class="node-icon">⚡</span>
          <span class="node-label">Cables</span>
        </div>
        <span class="flow-arrow">➔</span>
        <div class="flow-node">
          <span class="node-icon">🔌</span>
          <span class="node-label">Wall Socket</span>
        </div>
      </div>

      <div class="props-row">
        <div class="prop-chip">
          <span>⚡</span>
          <span>High Power<br><small style="color:#64748b;font-weight:normal;">230V Mains</small></span>
        </div>
        <div class="prop-chip">
          <span>🏠</span>
          <span>Stationary<br><small style="color:#64748b;font-weight:normal;">Stays Plugged In</small></span>
        </div>
      </div>

      <div class="appliances-grid">
        <div class="appliance-item">
          <span class="appliance-icon">🧊</span>
          <span>Fridge</span>
          <span class="status-badge mains-badge">Plug-in</span>
        </div>
        <div class="appliance-item">
          <span class="appliance-icon">📺</span>
          <span>TV</span>
          <span class="status-badge mains-badge">Plug-in</span>
        </div>
        <div class="appliance-item">
          <span class="appliance-icon">🧺</span>
          <span>Washer</span>
          <span class="status-badge mains-badge">Plug-in</span>
        </div>
      </div>
    </div>

    
    <div class="panel" id="panel-battery">
      <div class="flow-card">
        <div class="flow-node">
          <span class="node-icon">🔋</span>
          <span class="node-label">Cell</span>
        </div>
        <span class="flow-arrow">➔</span>
        <div class="flow-node">
          <span class="node-icon">⚡</span>
          <span class="node-label">Circuit</span>
        </div>
        <span class="flow-arrow">➔</span>
        <div class="flow-node">
          <span class="node-icon">📱</span>
          <span class="node-label">Device</span>
        </div>
      </div>

      <div class="props-row">
        <div class="prop-chip">
          <span>🛡️</span>
          <span>Low Voltage<br><small style="color:#64748b;font-weight:normal;">1.5V – 9V</small></span>
        </div>
        <div class="prop-chip">
          <span>🌳</span>
          <span>Portable<br><small style="color:#64748b;font-weight:normal;">Take Anywhere</small></span>
        </div>
      </div>

      <div class="appliances-grid">
        <div class="appliance-item">
          <span class="appliance-icon">🔦</span>
          <span>Torch</span>
          <span class="status-badge battery-badge">Portable</span>
        </div>
        <div class="appliance-item">
          <span class="appliance-icon">🚗</span>
          <span>Toy Car</span>
          <span class="status-badge battery-badge">Portable</span>
        </div>
        <div class="appliance-item">
          <span class="appliance-icon">⌚</span>
          <span>Watch</span>
          <span class="status-badge battery-badge">Portable</span>
        </div>
      </div>
    </div>
  </div>

  <script>
    function switchMode(mode) {
      const isMains = mode === 'mains';
      document.getElementById('btn-mains').classList.toggle('active', isMains);
      document.getElementById('btn-battery').classList.toggle('active', !isMains);
      document.getElementById('panel-mains').classList.toggle('active', isMains);
      document.getElementById('panel-battery').classList.toggle('active', !isMains);
    }
  </script>
</body>
</html>

What happens if you want to take an electric gadget outside to the park where there are no wall outlets?

Portable gadgets get their energy from **batteries**, which store electrical energy in compact chemical packs.

Batteries deliver a safe, steady flow of electricity that lets you carry devices like TV remotes, flashlights, and digital watches anywhere you go.

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <title>Mains vs Battery Power</title>
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; -webkit-tap-highlight-color: transparent; }
    body {
      font-family: system-ui, -apple-system, sans-serif;
      background: #f8fafc;
      color: #1e2945;
      padding: 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100%;
    }

    .nav-tabs {
      display: flex;
      gap: 8px;
      margin-bottom: 12px;
      width: 100%;
      max-width: 440px;
    }

    .tab-btn {
      flex: 1;
      border: 2px solid #e2e8f0;
      background: #ffffff;
      padding: 8px 12px;
      border-radius: 12px;
      font-size: 14px;
      font-weight: 700;
      color: #64748b;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      transition: all 0.25s ease;
    }

    .tab-btn.active {
      background: #f59e0b;
      border-color: #f59e0b;
      color: #ffffff;
      box-shadow: 0 4px 12px rgba(245, 158, 11, 0.25);
    }

    .stage {
      width: 100%;
      max-width: 440px;
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 16px;
      padding: 16px;
      display: flex;
      flex-direction: column;
      align-items: center;
      position: relative;
    }

    .display-area {
      width: 100%;
      height: 130px;
      background: #f8fafc;
      border-radius: 12px;
      border: 1px dashed #cbd5e1;
      display: flex;
      align-items: center;
      justify-content: center;
      position: relative;
      overflow: hidden;
      margin-bottom: 12px;
    }

    .power-source {
      position: absolute;
      left: 16px;
      display: flex;
      flex-direction: column;
      align-items: center;
      font-size: 26px;
    }

    .source-label {
      font-size: 11px;
      font-weight: 700;
      color: #64748b;
      margin-top: 2px;
      text-transform: uppercase;
      letter-spacing: 0.5px;
    }

    .target-device {
      position: absolute;
      right: 20px;
      display: flex;
      flex-direction: column;
      align-items: center;
      font-size: 40px;
      transition: transform 0.3s ease;
    }

    .cord-svg {
      position: absolute;
      inset: 0;
      width: 100%;
      height: 100%;
      pointer-events: none;
    }

    .cord-path {
      fill: none;
      stroke: #64748b;
      stroke-width: 4;
      stroke-linecap: round;
      transition: stroke 0.3s ease;
    }

    .spark {
      fill: none;
      stroke: #f59e0b;
      stroke-width: 4;
      stroke-dasharray: 8, 12;
      animation: flow 1.2s linear infinite;
    }

    @keyframes flow {
      to { stroke-dashoffset: -40; }
    }

    .battery-pack {
      display: none;
      align-items: center;
      gap: 4px;
      background: #fef3c7;
      border: 1.5px solid #f59e0b;
      padding: 4px 8px;
      border-radius: 8px;
      font-size: 12px;
      font-weight: 700;
      color: #b45309;
    }

    .status-badge {
      font-size: 13px;
      font-weight: 700;
      padding: 4px 10px;
      border-radius: 20px;
      display: inline-flex;
      align-items: center;
      gap: 4px;
      margin-bottom: 12px;
    }

    .badge-mains {
      background: #eff6ff;
      color: #2563eb;
      border: 1px solid #bfdbfe;
    }

    .badge-battery {
      background: #ecfdf5;
      color: #059669;
      border: 1px solid #a7f3d0;
    }

    .item-grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 8px;
      width: 100%;
    }

    .item-btn {
      background: #ffffff;
      border: 1.5px solid #e2e8f0;
      border-radius: 12px;
      padding: 8px 4px;
      cursor: pointer;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 4px;
      font-size: 12px;
      font-weight: 600;
      color: #475569;
      transition: all 0.2s ease;
    }

    .item-btn .emoji {
      font-size: 22px;
    }

    .item-btn.selected {
      border-color: #f59e0b;
      background: #fffbeb;
      color: #b45309;
      box-shadow: 0 2px 8px rgba(245, 158, 11, 0.15);
    }
  </style>
</head>
<body>

  <div class="nav-tabs">
    <button class="tab-btn active" id="tabMains" onclick="switchMode('mains')">
      <span>🔌</span> Mains
    </button>
    <button class="tab-btn" id="tabBattery" onclick="switchMode('battery')">
      <span>🔋</span> Battery
    </button>
  </div>

  <div class="stage">
    <div class="display-area" id="displayArea">
      <svg class="cord-svg" id="cordSvg" viewBox="0 0 400 130">
        <path id="cordBg" class="cord-path" d="M 60,65 C 160,110 240,20 330,65" />
        <path id="cordSpark" class="spark" d="M 60,65 C 160,110 240,20 330,65" />
      </svg>

      <div class="power-source" id="sourceIcon">
        <span id="sourceEmoji">🔌</span>
        <span class="source-label" id="sourceText">Wall Plug</span>
      </div>

      <div class="battery-pack" id="internalCell">
        <span>🔋</span> Inside
      </div>

      <div class="target-device" id="targetDevice">
        <span id="activeEmoji">🍞</span>
      </div>
    </div>

    <div class="status-badge badge-mains" id="featureBadge">
      ⚡ Fixed to Wall
    </div>

    <div class="item-grid" id="itemGrid"></div>
  </div>

  <script>
    const data = {
      mains: {
        badgeText: '⚡ Fixed to Wall',
        badgeClass: 'badge-mains',
        sourceEmoji: '🔌',
        sourceText: 'Wall Plug',
        items: [
          { name: 'Toaster', icon: '🍞' },
          { name: 'Kettle', icon: '🫖' },
          { name: 'Microwave', icon: '📻' }
        ]
      },
      battery: {
        badgeText: '🚶 Portable Anywhere',
        badgeClass: 'badge-battery',
        sourceEmoji: '🔋',
        sourceText: 'Cell Inside',
        items: [
          { name: 'Torch', icon: '🔦' },
          { name: 'Remote', icon: '📺' },
          { name: 'Watch', icon: '⌚' }
        ]
      }
    };

    let currentMode = 'mains';
    let selectedIdx = 0;

    function switchMode(mode) {
      currentMode = mode;
      selectedIdx = 0;
      
      document.getElementById('tabMains').classList.toggle('active', mode === 'mains');
      document.getElementById('tabBattery').classList.toggle('active', mode === 'battery');

      const isMains = mode === 'mains';
      document.getElementById('cordSvg').style.display = isMains ? 'block' : 'none';
      document.getElementById('sourceIcon').style.display = isMains ? 'flex' : 'none';
      document.getElementById('internalCell').style.display = isMains ? 'none' : 'flex';

      const badge = document.getElementById('featureBadge');
      badge.textContent = data[mode].badgeText;
      badge.className = 'status-badge ' + data[mode].badgeClass;

      renderItems();
    }

    function selectItem(idx) {
      selectedIdx = idx;
      renderItems();
    }

    function renderItems() {
      const modeData = data[currentMode];
      const activeItem = modeData.items[selectedIdx];
      
      document.getElementById('activeEmoji').textContent = activeItem.icon;

      const grid = document.getElementById('itemGrid');
      grid.innerHTML = '';

      modeData.items.forEach((item, i) => {
        const btn = document.createElement('button');
        btn.className = 'item-btn' + (i === selectedIdx ? ' selected' : '');
        btn.onclick = () => selectItem(i);
        btn.innerHTML = `<span class="emoji">${item.icon}</span><span>${item.name}</span>`;
        grid.appendChild(btn);
      });
    }

    // Initial render
    switchMode('mains');
  </script>
</body>
</html>

What about gadgets like tablets and smartphones that have a charging cord but also work freely in your hands?

Many modern electronics use **rechargeable batteries** hidden inside their cases.

When you plug them into the wall, they absorb mains electricity to fill up their battery storage, and then they run completely on battery power once unplugged.

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta name="aspect-ratio" content="4:3">
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
      font-family: system-ui, -apple-system, sans-serif;
      user-select: none;
    }

    body {
      background: #f8fafc;
      color: #1e2945;
      padding: 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      min-height: 100%;
    }

    .controls {
      display: flex;
      gap: 8px;
      margin-bottom: 14px;
      width: 100%;
      max-width: 420px;
    }

    .btn {
      flex: 1;
      padding: 10px 12px;
      border: 2px solid #e2e8f0;
      background: #ffffff;
      border-radius: 12px;
      font-size: 14px;
      font-weight: 700;
      color: #64748b;
      cursor: pointer;
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 6px;
      transition: background 0.2s, color 0.2s, border-color 0.2s, box-shadow 0.2s;
    }

    .btn.active {
      background: #ffffff;
      border-color: #22b7ff;
      color: #0284c7;
      box-shadow: 0 0 0 2px rgba(34, 183, 255, 0.2);
    }

    .stage {
      width: 100%;
      max-width: 420px;
      height: 250px;
      position: relative;
      background: #ffffff;
      border-radius: 16px;
      border: 1px solid #e2e8f0;
      display: flex;
      align-items: center;
      justify-content: space-between;
      padding: 20px;
      overflow: hidden;
    }

    /* Socket / Mains Side */
    .source-col {
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 8px;
      width: 90px;
      z-index: 2;
    }

    .socket-box {
      width: 64px;
      height: 64px;
      background: #fff5f5;
      border: 2px solid #fca5a5;
      border-radius: 12px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      position: relative;
    }

    .socket-holes {
      display: flex;
      gap: 8px;
    }

    .hole {
      width: 5px;
      height: 12px;
      background: #64748b;
      border-radius: 2px;
    }

    .hole.earth {
      width: 12px;
      height: 5px;
      position: absolute;
      top: 14px;
    }

    .badge-mains {
      font-size: 12px;
      font-weight: 800;
      background: #fee2e2;
      color: #ef4444;
      padding: 3px 8px;
      border-radius: 6px;
      letter-spacing: 0.5px;
    }

    /* Device / Phone Side */
    .device-col {
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 8px;
      width: 110px;
      z-index: 2;
    }

    .phone-box {
      width: 80px;
      height: 130px;
      background: #0f172a;
      border: 3px solid #334155;
      border-radius: 16px;
      padding: 6px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      box-shadow: 0 4px 12px rgba(0,0,0,0.08);
      position: relative;
    }

    .phone-screen {
      width: 100%;
      height: 100%;
      background: #1e293b;
      border-radius: 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      gap: 8px;
      transition: background 0.3s ease;
    }

    .screen-emoji {
      font-size: 26px;
      transition: transform 0.3s ease;
    }

    /* Battery Graphic inside phone */
    .battery-pill {
      width: 38px;
      height: 18px;
      border: 2px solid #94a3b8;
      border-radius: 4px;
      padding: 2px;
      position: relative;
    }

    .battery-pill::after {
      content: '';
      position: absolute;
      right: -5px;
      top: 4px;
      width: 3px;
      height: 6px;
      background: #94a3b8;
      border-radius: 0 2px 2px 0;
    }

    .battery-level {
      height: 100%;
      width: 100%;
      background: #10b981;
      border-radius: 2px;
      transition: width 0.4s ease, background-color 0.4s ease;
    }

    .badge-battery {
      font-size: 12px;
      font-weight: 800;
      background: #d1fae5;
      color: #059669;
      padding: 3px 8px;
      border-radius: 6px;
      letter-spacing: 0.5px;
    }

    /* Middle Connector & Cable */
    .connection-area {
      flex: 1;
      height: 100%;
      position: relative;
      display: flex;
      align-items: center;
      justify-content: center;
    }

    .cable-svg {
      position: absolute;
      width: 100%;
      height: 60px;
      top: 50%;
      transform: translateY(-50%);
      overflow: visible;
    }

    .cable-path {
      fill: none;
      stroke: #cbd5e1;
      stroke-width: 4;
      stroke-linecap: round;
      transition: stroke 0.3s ease;
    }

    .plug-head {
      width: 18px;
      height: 24px;
      background: #64748b;
      border-radius: 4px;
      position: absolute;
      top: 50%;
      transform: translateY(-50%);
      transition: left 0.4s cubic-bezier(0.34, 1.56, 0.64, 1), opacity 0.3s;
    }

    .pins {
      position: absolute;
      left: -6px;
      top: 4px;
      width: 6px;
      height: 16px;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
    }

    .pin {
      width: 6px;
      height: 4px;
      background: #d97706;
      border-radius: 1px;
    }

    /* State Visualizations */
    /* State 1: Plugged in (Charging) */
    .state-charging .cable-path {
      stroke: #ff9800;
      stroke-dasharray: 6 4;
      animation: dash 1s linear infinite;
    }

    .state-charging .plug-head {
      left: 2px;
      opacity: 1;
    }

    .state-charging .phone-screen {
      background: #0f372e;
    }

    .state-charging .battery-level {
      background: #22c55e;
      animation: chargePulse 1.5s ease-in-out infinite alternate;
    }

    /* State 2: Unplugged (Running on battery) */
    .state-unplugged .cable-path {
      stroke: #e2e8f0;
      stroke-dasharray: none;
    }

    .state-unplugged .plug-head {
      left: 36px;
      opacity: 0.4;
    }

    .state-unplugged .phone-screen {
      background: #0369a1;
    }

    .state-unplugged .screen-emoji {
      animation: bounce 2s infinite ease-in-out;
    }

    .state-unplugged .battery-level {
      background: #10b981;
      width: 80%;
    }

    /* Bottom Info Status */
    .status-bar {
      margin-top: 10px;
      font-size: 13px;
      font-weight: 700;
      display: flex;
      align-items: center;
      gap: 6px;
    }

    @keyframes dash {
      to {
        stroke-dashoffset: -20;
      }
    }

    @keyframes chargePulse {
      0% { opacity: 0.6; }
      100% { opacity: 1; }
    }

    @keyframes bounce {
      0%, 100% { transform: translateY(0); }
      50% { transform: translateY(-4px); }
    }
  </style>
</head>
<body>

  
  <div class="controls">
    <button class="btn active" id="btnCharging" onclick="setMode('charging')">
      <span>🔌</span> Plugged In
    </button>
    <button class="btn" id="btnUnplugged" onclick="setMode('unplugged')">
      <span>🔋</span> Unplugged
    </button>
  </div>

  
  <div class="stage state-charging" id="stage">
    
    
    <div class="source-col">
      <div class="socket-box">
        <div class="hole earth"></div>
        <div class="socket-holes" style="margin-top: 14px;">
          <div class="hole"></div>
          <div class="hole"></div>
        </div>
      </div>
      <span class="badge-mains">⚡ Mains</span>
    </div>

    
    <div class="connection-area">
      <svg class="cable-svg" viewBox="0 0 160 60">
        <path id="wire" class="cable-path" d="M 12 30 Q 80 50 148 30" />
      </svg>
      
      <div class="plug-head" id="plug">
        <div class="pins">
          <div class="pin"></div>
          <div class="pin"></div>
        </div>
      </div>
    </div>

    
    <div class="device-col">
      <div class="phone-box">
        <div class="phone-screen">
          <div class="screen-emoji" id="screenIcon">⚡</div>
          <div class="battery-pill">
            <div class="battery-level"></div>
          </div>
        </div>
      </div>
      <span class="badge-battery">🔋 Battery</span>
    </div>

  </div>

  
  <div class="status-bar" id="statusBar">
    <span>⚡</span> Mains fills internal battery
  </div>

  <script>
    function setMode(mode) {
      const stage = document.getElementById('stage');
      const btnCharging = document.getElementById('btnCharging');
      const btnUnplugged = document.getElementById('btnUnplugged');
      const screenIcon = document.getElementById('screenIcon');
      const statusBar = document.getElementById('statusBar');

      if (mode === 'charging') {
        stage.className = 'stage state-charging';
        btnCharging.className = 'btn active';
        btnUnplugged.className = 'btn';
        screenIcon.textContent = '⚡';
        statusBar.innerHTML = '<span>⚡</span> Mains fills internal battery';
        statusBar.style.color = '#d97706';
      } else {
        stage.className = 'stage state-unplugged';
        btnCharging.className = 'btn';
        btnUnplugged.className = 'btn active';
        screenIcon.textContent = '📱';
        statusBar.innerHTML = '<span>🔋</span> Stored battery powers phone';
        statusBar.style.color = '#059669';
      }
    }
  </script>
</body>
</html>

A common mistake is thinking a smartphone is mains-powered because you see a charging cable plugged into the wall.

Remember: if an appliance can keep playing music or lighting up while you walk around the room with it, it is running on battery power!

science

Identifying Mains Electricity Versus Battery-Powered Appliances. Distinguish between everyday appliances that run on mains electricity and those that run on portable batteries.

Electrical Appliances (KS2 Science / Year 4)

Electricity and Electrical Appliances in Daily Life (Primary Science)

Electricity in the Home: Mains vs. Battery Power

Teaching this objective is most effective when grounded in concrete, multisensory sorting tasks and classroom 'appliance scavenger hunts'. Begin with visible features (plugs, wires, battery compartments) before linking the power source to appliance function (high thermal/mechanical power demands mains electricity, whereas mobility and low power demand batteries). Address the bridge category of modern rechargeable devices explicitly using a Venn diagram to resolve the cognitive conflict between battery storage and mains recharging.

Identifying Mains Electricity Versus Battery-Powered Appliances

Mains Electricity

Battery Power

The Rechargeable Clue