<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      background: #ffffff;
      color: #0f172a;
      padding: 8px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: flex-start;
      min-height: 100vh;
    }

    .controls-container {
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 4px;
      margin-bottom: 8px;
      width: 100%;
      max-width: 660px;
    }

    .controls {
      display: flex;
      gap: 6px;
      background: #e2e8f0;
      padding: 3px;
      border-radius: 20px;
    }

    .btn {
      padding: 5px 14px;
      font-size: 12px;
      font-weight: 700;
      border-radius: 16px;
      border: none;
      background: transparent;
      color: #334155;
      cursor: pointer;
      transition: background 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
    }

    .btn:hover {
      color: #0f172a;
    }

    .btn.active {
      background: #1d4ed8;
      color: #ffffff;
      box-shadow: 0 1px 4px rgba(29, 78, 216, 0.35);
    }

    .status-banner {
      font-size: 11.5px;
      font-weight: 600;
      color: #475569;
      text-align: center;
      min-height: 16px;
      transition: color 0.25s ease;
    }

    .grid {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 8px;
      width: 100%;
      max-width: 660px;
    }

    .panel {
      background: #f8fafc;
      border: 1px solid #cbd5e1;
      border-radius: 8px;
      padding: 8px 6px;
      display: flex;
      flex-direction: column;
      align-items: center;
      text-align: center;
      position: relative;
    }

    .panel-header {
      margin-bottom: 4px;
      width: 100%;
    }

    .title {
      font-size: 13px;
      font-weight: 700;
      color: #0f172a;
      line-height: 1.2;
    }

    .subtitle {
      font-size: 10.5px;
      font-weight: 600;
      color: #475569;
      min-height: 28px;
      display: flex;
      align-items: center;
      justify-content: center;
      line-height: 1.2;
      transition: color 0.25s ease;
    }

    .svg-wrap {
      width: 100%;
      max-width: 170px;
      aspect-ratio: 1 / 1.1;
      position: relative;
    }

    svg {
      width: 100%;
      height: 100%;
      display: block;
    }

    /* SVG Component Styles */
    .field-line {
      fill: none;
      stroke-width: 1.6;
      stroke-dasharray: 4 2.5;
      opacity: 0;
      transition: opacity 0.3s ease;
    }

    .field-on .field-line {
      opacity: 0.95;
    }

    .dia-line { stroke: #64748b; }
    .para-line { stroke: #2563eb; }
    .ferro-line { stroke: #dc2626; stroke-width: 2; }

    .sample-box {
      fill: #ffffff;
      stroke: #475569;
      stroke-width: 1.5;
      rx: 6;
    }

    .rot-target {
      transform-origin: 0 0;
      transition: transform 0.4s cubic-bezier(0.34, 1.25, 0.64, 1);
    }

    .ext-b {
      opacity: 0;
      transition: opacity 0.25s ease;
    }

    .field-on .ext-b {
      opacity: 1;
    }

    .dia-pair {
      transition: opacity 0.3s ease;
    }

    .field-on .dia-pair {
      opacity: 0.1;
    }

    .field-off .dia-pair {
      opacity: 1;
    }

    .dia-dipole {
      transition: opacity 0.3s ease, transform 0.3s ease;
      transform-origin: center;
    }

    .field-on .dia-dipole {
      opacity: 1;
      transform: translateY(0);
    }

    .field-off .dia-dipole {
      opacity: 0;
      transform: translateY(-4px);
    }

    .domain-wall {
      transition: opacity 0.35s ease;
    }

    .field-on .domain-wall {
      opacity: 0.08;
    }

    /* Responsive Mobile Layout */
    @media (max-width: 500px) {
      body {
        padding: 4px;
      }

      .grid {
        grid-template-columns: 1fr;
        gap: 6px;
      }

      .panel {
        flex-direction: row;
        justify-content: space-between;
        align-items: center;
        padding: 4px 10px;
        text-align: left;
      }

      .panel-header {
        flex: 1;
        margin-bottom: 0;
        padding-right: 8px;
      }

      .subtitle {
        justify-content: flex-start;
        min-height: auto;
        margin-top: 2px;
      }

      .svg-wrap {
        width: 110px;
        max-width: 110px;
        aspect-ratio: 1 / 1;
      }
    }
  </style>
</head>
<body class="field-off">

  <div class="controls-container">
    <div class="controls">
      <button class="btn active" id="btnOff">Field OFF (B = 0)</button>
      <button class="btn" id="btnOn">Field ON (B<sub>ext</sub> ↑)</button>
    </div>
    <div class="status-banner" id="statusBanner">No applied magnetic field — thermal/random equilibrium</div>
  </div>

  <div class="grid" id="mainContainer">
    
    <div class="panel">
      <div class="panel-header">
        <div class="title">Diamagnetic</div>
        <div class="subtitle" id="diaSub">Paired electrons (net dipole = 0)</div>
      </div>
      <div class="svg-wrap">
        <svg viewBox="0 0 140 145">
          <defs>
            <marker id="m-ext" markerWidth="4" markerHeight="4" refX="2" refY="2" orient="auto">
              <path d="M0,0 L4,2 L0,4 Z" fill="#1d4ed8" />
            </marker>
            <marker id="m-dia" markerWidth="4" markerHeight="4" refX="2" refY="2" orient="auto">
              <path d="M0,0 L4,2 L0,4 Z" fill="#1e293b" />
            </marker>
            <marker id="m-para" markerWidth="4" markerHeight="4" refX="2" refY="2" orient="auto">
              <path d="M0,0 L4,2 L0,4 Z" fill="#1d4ed8" />
            </marker>
            <marker id="m-ferro" markerWidth="4" markerHeight="4" refX="2" refY="2" orient="auto">
              <path d="M0,0 L4,2 L0,4 Z" fill="#dc2626" />
            </marker>
          </defs>

          
          <g class="ext-b">
            <line x1="12" y1="128" x2="12" y2="24" stroke="#1d4ed8" stroke-width="2" marker-end="url(#m-ext)"/>
            <text x="12" y="14" font-size="10" font-weight="bold" fill="#1d4ed8" text-anchor="middle">B</text>
          </g>

          
          <g class="field-line dia-line">
            <path d="M 32 138 C 32 102, 16 88, 16 72 C 16 56, 32 42, 32 8" />
            <path d="M 52 138 C 52 106, 34 89, 34 72 C 34 55, 52 38, 52 8" />
            <path d="M 88 138 C 88 106, 106 89, 106 72 C 106 55, 88 38, 88 8" />
            <path d="M 108 138 C 108 102, 124 88, 124 72 C 124 56, 108 42, 108 8" />
          </g>

          
          <rect class="sample-box" x="38" y="28" width="64" height="88"/>

          
          <g class="dia-pair">
            <circle cx="54" cy="52" r="10" fill="none" stroke="#94a3b8" stroke-width="1.2" stroke-dasharray="2 1.5"/>
            <text x="54" y="56" font-size="11" font-weight="bold" fill="#475569" text-anchor="middle">⇅</text>
            <circle cx="86" cy="52" r="10" fill="none" stroke="#94a3b8" stroke-width="1.2" stroke-dasharray="2 1.5"/>
            <text x="86" y="56" font-size="11" font-weight="bold" fill="#475569" text-anchor="middle">⇅</text>
            <circle cx="54" cy="92" r="10" fill="none" stroke="#94a3b8" stroke-width="1.2" stroke-dasharray="2 1.5"/>
            <text x="54" y="96" font-size="11" font-weight="bold" fill="#475569" text-anchor="middle">⇅</text>
            <circle cx="86" cy="92" r="10" fill="none" stroke="#94a3b8" stroke-width="1.2" stroke-dasharray="2 1.5"/>
            <text x="86" y="96" font-size="11" font-weight="bold" fill="#475569" text-anchor="middle">⇅</text>
          </g>

          
          <g class="dia-dipole">
            <line x1="54" y1="42" x2="54" y2="62" stroke="#1e293b" stroke-width="2.5" marker-end="url(#m-dia)"/>
            <line x1="86" y1="42" x2="86" y2="62" stroke="#1e293b" stroke-width="2.5" marker-end="url(#m-dia)"/>
            <line x1="54" y1="82" x2="54" y2="102" stroke="#1e293b" stroke-width="2.5" marker-end="url(#m-dia)"/>
            <line x1="86" y1="82" x2="86" y2="102" stroke="#1e293b" stroke-width="2.5" marker-end="url(#m-dia)"/>
          </g>
        </svg>
      </div>
    </div>

    
    <div class="panel">
      <div class="panel-header">
        <div class="title">Paramagnetic</div>
        <div class="subtitle" id="paraSub">Random thermal dipoles</div>
      </div>
      <div class="svg-wrap">
        <svg viewBox="0 0 140 145">
          
          <g class="ext-b">
            <line x1="12" y1="128" x2="12" y2="24" stroke="#1d4ed8" stroke-width="2" marker-end="url(#m-ext)"/>
            <text x="12" y="14" font-size="10" font-weight="bold" fill="#1d4ed8" text-anchor="middle">B</text>
          </g>

          
          <g class="field-line para-line">
            <path d="M 26 138 C 26 102, 42 88, 42 72 C 42 56, 26 42, 26 8" />
            <path d="M 52 138 C 52 98, 60 88, 60 72 C 60 56, 52 46, 52 8" />
            <path d="M 88 138 C 88 98, 80 88, 80 72 C 80 56, 88 46, 88 8" />
            <path d="M 114 138 C 114 102, 98 88, 98 72 C 98 56, 114 42, 114 8" />
          </g>

          
          <rect class="sample-box" x="38" y="28" width="64" height="88"/>

          
          <g id="paraArrows">
            
            <g transform="translate(54, 46)">
              <g class="rot-target" data-off="-75" data-on="-5">
                <line x1="0" y1="8" x2="0" y2="-8" stroke="#1d4ed8" stroke-width="2.2" marker-end="url(#m-para)"/>
              </g>
            </g>
            <g transform="translate(86, 46)">
              <g class="rot-target" data-off="110" data-on="6">
                <line x1="0" y1="8" x2="0" y2="-8" stroke="#1d4ed8" stroke-width="2.2" marker-end="url(#m-para)"/>
              </g>
            </g>
            
            <g transform="translate(54, 72)">
              <g class="rot-target" data-off="145" data-on="-3">
                <line x1="0" y1="8" x2="0" y2="-8" stroke="#1d4ed8" stroke-width="2.2" marker-end="url(#m-para)"/>
              </g>
            </g>
            <g transform="translate(86, 72)">
              <g class="rot-target" data-off="-135" data-on="4">
                <line x1="0" y1="8" x2="0" y2="-8" stroke="#1d4ed8" stroke-width="2.2" marker-end="url(#m-para)"/>
              </g>
            </g>
            
            <g transform="translate(54, 98)">
              <g class="rot-target" data-off="45" data-on="-6">
                <line x1="0" y1="8" x2="0" y2="-8" stroke="#1d4ed8" stroke-width="2.2" marker-end="url(#m-para)"/>
              </g>
            </g>
            <g transform="translate(86, 98)">
              <g class="rot-target" data-off="-40" data-on="5">
                <line x1="0" y1="8" x2="0" y2="-8" stroke="#1d4ed8" stroke-width="2.2" marker-end="url(#m-para)"/>
              </g>
            </g>
          </g>
        </svg>
      </div>
    </div>

    
    <div class="panel">
      <div class="panel-header">
        <div class="title">Ferromagnetic</div>
        <div class="subtitle" id="ferroSub">Multi-domain structure</div>
      </div>
      <div class="svg-wrap">
        <svg viewBox="0 0 140 145">
          
          <g class="ext-b">
            <line x1="12" y1="128" x2="12" y2="24" stroke="#1d4ed8" stroke-width="2" marker-end="url(#m-ext)"/>
            <text x="12" y="14" font-size="10" font-weight="bold" fill="#1d4ed8" text-anchor="middle">B</text>
          </g>

          
          <g class="field-line ferro-line">
            <path d="M 16 138 C 16 102, 46 92, 46 72 C 46 52, 16 42, 16 8" />
            <path d="M 40 138 C 40 96, 58 86, 58 72 C 58 58, 40 48, 40 8" />
            <path d="M 100 138 C 100 96, 82 86, 82 72 C 82 58, 100 48, 100 8" />
            <path d="M 124 138 C 124 102, 94 92, 94 72 C 94 52, 124 42, 124 8" />
          </g>

          
          <rect class="sample-box" x="38" y="28" width="64" height="88"/>

          
          <g class="domain-wall">
            <line x1="38" y1="72" x2="102" y2="72" stroke="#64748b" stroke-width="1.3" stroke-dasharray="3 2"/>
            <line x1="70" y1="28" x2="70" y2="116" stroke="#64748b" stroke-width="1.3" stroke-dasharray="3 2"/>
          </g>

          
          <g id="ferroArrows">
            
            <g transform="translate(48, 50)">
              <g class="rot-target" data-off="-90" data-on="0">
                <line x1="0" y1="8" x2="0" y2="-8" stroke="#dc2626" stroke-width="2.4" marker-end="url(#m-ferro)"/>
              </g>
            </g>
            <g transform="translate(60, 50)">
              <g class="rot-target" data-off="-90" data-on="0">
                <line x1="0" y1="8" x2="0" y2="-8" stroke="#dc2626" stroke-width="2.4" marker-end="url(#m-ferro)"/>
              </g>
            </g>

            
            <g transform="translate(80, 50)">
              <g class="rot-target" data-off="0" data-on="0">
                <line x1="0" y1="8" x2="0" y2="-8" stroke="#dc2626" stroke-width="2.4" marker-end="url(#m-ferro)"/>
              </g>
            </g>
            <g transform="translate(92, 50)">
              <g class="rot-target" data-off="0" data-on="0">
                <line x1="0" y1="8" x2="0" y2="-8" stroke="#dc2626" stroke-width="2.4" marker-end="url(#m-ferro)"/>
              </g>
            </g>

            
            <g transform="translate(48, 94)">
              <g class="rot-target" data-off="180" data-on="0">
                <line x1="0" y1="8" x2="0" y2="-8" stroke="#dc2626" stroke-width="2.4" marker-end="url(#m-ferro)"/>
              </g>
            </g>
            <g transform="translate(60, 94)">
              <g class="rot-target" data-off="180" data-on="0">
                <line x1="0" y1="8" x2="0" y2="-8" stroke="#dc2626" stroke-width="2.4" marker-end="url(#m-ferro)"/>
              </g>
            </g>

            
            <g transform="translate(80, 94)">
              <g class="rot-target" data-off="90" data-on="0">
                <line x1="0" y1="8" x2="0" y2="-8" stroke="#dc2626" stroke-width="2.4" marker-end="url(#m-ferro)"/>
              </g>
            </g>
            <g transform="translate(92, 94)">
              <g class="rot-target" data-off="90" data-on="0">
                <line x1="0" y1="8" x2="0" y2="-8" stroke="#dc2626" stroke-width="2.4" marker-end="url(#m-ferro)"/>
              </g>
            </g>
          </g>
        </svg>
      </div>
    </div>
  </div>

  <script>
    const btnOff = document.getElementById('btnOff');
    const btnOn = document.getElementById('btnOn');
    const rotTargets = document.querySelectorAll('.rot-target');
    const statusBanner = document.getElementById('statusBanner');
    const diaSub = document.getElementById('diaSub');
    const paraSub = document.getElementById('paraSub');
    const ferroSub = document.getElementById('ferroSub');

    function setFieldState(isOn) {
      if (isOn) {
        document.body.classList.remove('field-off');
        document.body.classList.add('field-on');
        btnOn.classList.add('active');
        btnOff.classList.remove('active');
        
        statusBanner.textContent = 'Applied field B_ext (↑) induces distinct magnetic behaviors';
        statusBanner.style.color = '#1d4ed8';
        diaSub.textContent = 'Induced opposing dipoles (weakly repelled)';
        diaSub.style.color = '#334155';
        paraSub.textContent = 'Partial alignment with field (weakly attracted)';
        paraSub.style.color = '#1d4ed8';
        ferroSub.textContent = 'Domains align strongly (strongly attracted)';
        ferroSub.style.color = '#dc2626';
      } else {
        document.body.classList.remove('field-on');
        document.body.classList.add('field-off');
        btnOff.classList.add('active');
        btnOn.classList.remove('active');

        statusBanner.textContent = 'No applied magnetic field — thermal/random equilibrium';
        statusBanner.style.color = '#475569';
        diaSub.textContent = 'Paired electrons (net dipole = 0)';
        diaSub.style.color = '#475569';
        paraSub.textContent = 'Random thermal dipoles (net dipole = 0)';
        paraSub.style.color = '#475569';
        ferroSub.textContent = 'Multi-domain structure (net dipole = 0)';
        ferroSub.style.color = '#475569';
      }

      rotTargets.forEach(target => {
        const deg = isOn ? target.dataset.on : target.dataset.off;
        target.style.transform = `rotate(${deg}deg)`;
      });
    }

    btnOff.addEventListener('click', () => setFieldState(false));
    btnOn.addEventListener('click', () => setFieldState(true));

    // Initialize in field-off state
    setFieldState(false);
  </script>
</body>
</html>

Permanent Versus Induced Magnets and Magnetic Materials

<!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; }
    body {
      font-family: system-ui, -apple-system, sans-serif;
      background: #ffffff;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: space-between;
      min-height: 100%;
      padding: 12px 16px;
      user-select: none;
    }

    /* Top external field indicator */
    .b-ext-bar {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 8px;
      height: 32px;
      font-size: 14px;
      font-weight: 700;
      color: #64748b;
      transition: color 0.4s ease;
    }
    .b-ext-bar.active-weak { color: #0284c7; }
    .b-ext-bar.active-strong { color: #0369a1; }
    .b-arrows {
      display: inline-flex;
      gap: 4px;
      letter-spacing: 2px;
      font-size: 16px;
    }

    /* Diagram visual container */
    .stage-canvas {
      width: 100%;
      max-width: 440px;
      height: 230px;
      position: relative;
    }

    svg {
      width: 100%;
      height: 100%;
      overflow: visible;
    }

    /* Domain shapes & transitions */
    .domain-wall {
      stroke: #334155;
      stroke-width: 2.5;
      stroke-dasharray: 4 3;
      fill: none;
      transition: opacity 0.5s ease;
    }

    .domain-patch {
      transition: d 0.6s cubic-bezier(0.4, 0, 0.2, 1), fill 0.5s ease, opacity 0.5s ease;
    }

    .arrow-group {
      transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
      transform-origin: center;
    }

    /* Net Magnetization Meter */
    .net-meter {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 10px;
      font-size: 14px;
      font-weight: 700;
      padding: 6px 14px;
      background: #f1f5f9;
      border-radius: 20px;
      margin: 4px 0;
    }
    .net-arrow {
      display: inline-block;
      transition: transform 0.5s ease, width 0.5s ease;
      font-size: 18px;
      color: #0284c7;
    }

    /* Step control bar */
    .controls {
      display: flex;
      gap: 8px;
      align-items: center;
      justify-content: center;
      flex-wrap: wrap;
      margin-top: 4px;
    }

    .btn {
      background: #f8fafc;
      border: 1px solid #cbd5e1;
      color: #475569;
      padding: 6px 12px;
      border-radius: 8px;
      font-size: 13px;
      font-weight: 600;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      gap: 4px;
      transition: background 0.2s, color 0.2s, border-color 0.2s, box-shadow 0.2s;
    }
    .btn:hover {
      background: #f1f5f9;
      color: #1e2945;
    }
    .btn.active {
      background: #0284c7;
      color: #ffffff;
      border-color: #0284c7;
      box-shadow: 0 2px 6px rgba(2, 132, 199, 0.25);
    }
    .btn-play {
      padding: 6px 10px;
    }
  </style>
</head>
<body>

  
  <div class="b-ext-bar" id="bExtBar">
    <span id="bExtLabel">External Field (B<sub>ext</sub> = 0)</span>
    <span class="b-arrows" id="bExtArrows"></span>
  </div>

  
  <div class="stage-canvas">
    <svg viewBox="0 0 400 210">
      <defs>
        
        <marker id="arr" viewBox="0 0 10 10" refX="6" refY="5" markerWidth="4.5" markerHeight="4.5" orient="auto-start-reverse">
          <path d="M 1 1.5 L 8 5 L 1 8.5 z" fill="currentColor" />
        </marker>
        <marker id="arr-blue" viewBox="0 0 10 10" refX="6" refY="5" markerWidth="4.5" markerHeight="4.5" orient="auto-start-reverse">
          <path d="M 1 1.5 L 8 5 L 1 8.5 z" fill="#0284c7" />
        </marker>
        <clipPath id="block-clip">
          <rect x="25" y="10" width="350" height="190" rx="12" />
        </clipPath>
      </defs>

      
      <g clip-path="url(#block-clip)">
        
        <path id="patch1" class="domain-patch" fill="#f8fafc" />
        <path id="patch2" class="domain-patch" fill="#f1f5f9" />
        <path id="patch3" class="domain-patch" fill="#e2e8f0" />
        <path id="patch4" class="domain-patch" fill="#e0f2fe" />

        
        <path id="wallH" class="domain-wall" />
        <path id="wallV1" class="domain-wall" />
        <path id="wallV2" class="domain-wall" />

        
        <g id="grp1" class="arrow-group" style="color: #64748b;">
          <line x1="75" y1="45" x2="75" y2="75" stroke="currentColor" stroke-width="2.5" marker-end="url(#arr)" />
          <line x1="125" y1="45" x2="125" y2="75" stroke="currentColor" stroke-width="2.5" marker-end="url(#arr)" />
        </g>

        
        <g id="grp2" class="arrow-group" style="color: #64748b;">
          <line x1="75" y1="165" x2="75" y2="135" stroke="currentColor" stroke-width="2.5" marker-end="url(#arr)" />
          <line x1="125" y1="165" x2="125" y2="135" stroke="currentColor" stroke-width="2.5" marker-end="url(#arr)" />
        </g>

        
        <g id="grp3" class="arrow-group" style="color: #64748b;">
          <line x1="250" y1="60" x2="220" y2="60" stroke="currentColor" stroke-width="2.5" marker-end="url(#arr)" />
          <line x1="310" y1="60" x2="280" y2="60" stroke="currentColor" stroke-width="2.5" marker-end="url(#arr)" />
        </g>

        
        <g id="grp4" class="arrow-group" style="color: #0284c7;">
          <line x1="220" y1="150" x2="255" y2="150" stroke="#0284c7" stroke-width="2.5" marker-end="url(#arr-blue)" />
          <line x1="290" y1="150" x2="325" y2="150" stroke="#0284c7" stroke-width="2.5" marker-end="url(#arr-blue)" />
          <line id="extraArr1" x1="155" y1="105" x2="190" y2="105" stroke="#0284c7" stroke-width="2.5" marker-end="url(#arr-blue)" opacity="0" />
          <line id="extraArr2" x1="155" y1="150" x2="190" y2="150" stroke="#0284c7" stroke-width="2.5" marker-end="url(#arr-blue)" opacity="0" />
          <line id="extraArr3" x1="220" y1="105" x2="255" y2="105" stroke="#0284c7" stroke-width="2.5" marker-end="url(#arr-blue)" opacity="0" />
        </g>
      </g>

      
      <rect x="25" y="10" width="350" height="190" rx="12" fill="none" stroke="#475569" stroke-width="3" />
    </svg>
  </div>

  
  <div class="net-meter" id="netMeter">
    <span>Net Magnetization:</span>
    <span id="netText" style="color: #64748b;">Net B = 0</span>
  </div>

  
  <div class="controls">
    <button class="btn btn-play" id="playBtn" title="Auto play">⏸</button>
    <button class="btn active" id="btn0">1. Unmagnetized</button>
    <button class="btn" id="btn1">2. Weak Field</button>
    <button class="btn" id="btn2">3. Saturation</button>
  </div>

  <script>
    const stages = [
      {
        bExtText: "External Field (B<sub>ext</sub> = 0)",
        bExtClass: "",
        bArrows: "",
        wallOpacity: 1,
        wallH: "M 25 105 L 375 105",
        wallV1: "M 180 10 L 180 105",
        wallV2: "M 180 105 L 180 200",
        patch1: "M 25 10 L 180 10 L 180 105 L 25 105 Z",
        patch2: "M 25 105 L 180 105 L 180 200 L 25 200 Z",
        patch3: "M 180 10 L 375 10 L 375 105 L 180 105 Z",
        patch4: "M 180 105 L 375 105 L 375 200 L 180 200 Z",
        rot1: 0, rot2: 0, rot3: 0,
        extraArrOpacity: 0,
        netHTML: "<span style='color:#64748b'>Net B = 0</span>"
      },
      {
        bExtText: "External Field (Weak B<sub>ext</sub>)",
        bExtClass: "active-weak",
        bArrows: "→ →",
        wallOpacity: 0.8,
        wallH: "M 25 70 Q 100 65 110 50 L 110 10",
        wallV1: "M 110 10 L 110 50",
        wallV2: "M 110 50 L 110 200",
        patch1: "M 25 10 L 110 10 L 110 50 L 25 70 Z",
        patch2: "M 25 70 L 110 50 L 110 200 L 25 200 Z",
        patch3: "M 110 10 L 375 10 L 375 50 L 220 50 Z",
        patch4: "M 25 70 L 110 50 L 220 50 L 375 50 L 375 200 L 110 200 Z",
        rot1: 25, rot2: -25, rot3: 0,
        extraArrOpacity: 1,
        netHTML: "<span style='color:#0284c7'>Net B → (Weak)</span>"
      },
      {
        bExtText: "External Field (Strong B<sub>ext</sub>)",
        bExtClass: "active-strong",
        bArrows: "➔ ➔ ➔",
        wallOpacity: 0,
        wallH: "M 25 10 L 25 10",
        wallV1: "M 25 10 L 25 10",
        wallV2: "M 25 10 L 25 10",
        patch1: "M 25 10 L 25 10 L 25 10 L 25 10 Z",
        patch2: "M 25 200 L 25 200 L 25 200 L 25 200 Z",
        patch3: "M 375 10 L 375 10 L 375 10 L 375 10 Z",
        patch4: "M 25 10 L 375 10 L 375 200 L 25 200 Z",
        rot1: 90, rot2: 90, rot3: 180,
        extraArrOpacity: 1,
        netHTML: "<span style='color:#0369a1'>Net B ➔ (Saturated)</span>"
      }
    ];

    let currentStep = 0;
    let timer = null;
    let isPlaying = true;

    const bExtBar = document.getElementById('bExtBar');
    const bExtLabel = document.getElementById('bExtLabel');
    const bExtArrows = document.getElementById('bExtArrows');
    const netText = document.getElementById('netText');
    const playBtn = document.getElementById('playBtn');

    const wallH = document.getElementById('wallH');
    const wallV1 = document.getElementById('wallV1');
    const wallV2 = document.getElementById('wallV2');
    const patch1 = document.getElementById('patch1');
    const patch2 = document.getElementById('patch2');
    const patch3 = document.getElementById('patch3');
    const patch4 = document.getElementById('patch4');

    const grp1 = document.getElementById('grp1');
    const grp2 = document.getElementById('grp2');
    const grp3 = document.getElementById('grp3');
    const extra1 = document.getElementById('extraArr1');
    const extra2 = document.getElementById('extraArr2');
    const extra3 = document.getElementById('extraArr3');

    const btns = [
      document.getElementById('btn0'),
      document.getElementById('btn1'),
      document.getElementById('btn2')
    ];

    function applyStage(idx) {
      currentStep = idx;
      const s = stages[idx];

      // External field header
      bExtLabel.innerHTML = s.bExtText;
      bExtArrows.textContent = s.bArrows;
      bExtBar.className = 'b-ext-bar ' + s.bExtClass;

      // Net Magnetization
      netText.innerHTML = s.netHTML;

      // Domain Wall strokes
      wallH.style.opacity = s.wallOpacity;
      wallV1.style.opacity = s.wallOpacity;
      wallV2.style.opacity = s.wallOpacity;
      wallH.setAttribute('d', s.wallH);
      wallV1.setAttribute('d', s.wallV1);
      wallV2.setAttribute('d', s.wallV2);

      // Domain Patches
      patch1.setAttribute('d', s.patch1);
      patch2.setAttribute('d', s.patch2);
      patch3.setAttribute('d', s.patch3);
      patch4.setAttribute('d', s.patch4);

      // Group Arrow rotations & colors
      grp1.style.transform = `rotate(${s.rot1}deg)`;
      grp1.style.transformOrigin = "100px 60px";
      grp1.style.color = idx === 2 ? '#0284c7' : '#64748b';

      grp2.style.transform = `rotate(${s.rot2}deg)`;
      grp2.style.transformOrigin = "100px 150px";
      grp2.style.color = idx === 2 ? '#0284c7' : '#64748b';

      grp3.style.transform = `rotate(${s.rot3}deg)`;
      grp3.style.transformOrigin = "280px 60px";
      grp3.style.color = idx === 2 ? '#0284c7' : '#64748b';

      extra1.style.opacity = s.extraArrOpacity;
      extra2.style.opacity = s.extraArrOpacity;
      extra3.style.opacity = s.extraArrOpacity;

      // Buttons
      btns.forEach((b, i) => {
        b.classList.toggle('active', i === idx);
      });
    }

    function nextStep() {
      applyStage((currentStep + 1) % stages.length);
    }

    function startAutoPlay() {
      if (timer) clearInterval(timer);
      timer = setInterval(nextStep, 3200);
      isPlaying = true;
      playBtn.textContent = '⏸';
    }

    function pauseAutoPlay() {
      if (timer) clearInterval(timer);
      timer = null;
      isPlaying = false;
      playBtn.textContent = '▶';
    }

    btns.forEach((btn, i) => {
      btn.addEventListener('click', () => {
        pauseAutoPlay();
        applyStage(i);
      });
    });

    playBtn.addEventListener('click', () => {
      if (isPlaying) {
        pauseAutoPlay();
      } else {
        nextStep();
        startAutoPlay();
      }
    });

    // Init
    applyStage(0);
    startAutoPlay();
  </script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Soft vs Hard Magnetic Materials</title>
  <style>
    * { box-sizing: border-box; margin: 0; padding: 0; }
    body {
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      color: #0f172a;
      background: transparent;
      padding: 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 10px;
      min-height: 100%;
      overflow-x: hidden;
    }

    /* Controls */
    .controls-wrapper {
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 6px;
      width: 100%;
      max-width: 560px;
    }
    .controls {
      display: flex;
      gap: 8px;
      align-items: center;
      justify-content: center;
      width: 100%;
    }
    .btn {
      appearance: none;
      border: 1.5px solid #cbd5e1;
      background: #ffffff;
      padding: 6px 16px;
      border-radius: 20px;
      font-size: 13px;
      font-weight: 600;
      color: #334155;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      transition: background-color 0.2s ease, border-color 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
    }
    .btn:hover {
      border-color: #94a3b8;
      background: #f8fafc;
    }
    .btn.active {
      background: #0284c7;
      border-color: #0284c7;
      color: #ffffff;
      box-shadow: 0 2px 6px rgba(2, 132, 199, 0.35);
    }

    /* Comparison Grid */
    .grid {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 12px;
      width: 100%;
      max-width: 560px;
    }
    @media (max-width: 440px) {
      .grid {
        grid-template-columns: 1fr;
        gap: 10px;
      }
    }

    .panel {
      background: #ffffff;
      border: 1px solid #e2e8f0;
      border-radius: 10px;
      padding: 10px;
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 6px;
      box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    }

    .panel-header {
      text-align: center;
      width: 100%;
    }
    .title {
      font-size: 14px;
      font-weight: 700;
      color: #0f172a;
      line-height: 1.2;
    }
    .sub {
      font-size: 11px;
      color: #64748b;
      font-weight: 500;
      margin-top: 2px;
    }

    .svg-wrap {
      width: 100%;
      max-width: 220px;
      aspect-ratio: 200 / 155;
    }
    svg {
      width: 100%;
      height: 100%;
      display: block;
      overflow: hidden;
    }

    /* Domain transitions */
    .wall {
      transition: opacity 0.4s ease-in-out;
    }
    .arrow-line {
      transition: transform 0.45s cubic-bezier(0.4, 0, 0.2, 1), stroke 0.3s ease;
      transform-origin: 0px 0px;
    }

    .status-badge {
      font-size: 11px;
      font-weight: 700;
      padding: 3px 10px;
      border-radius: 12px;
      transition: background-color 0.3s ease, color 0.3s ease;
      text-align: center;
      width: fit-content;
    }
    .status-off {
      background: #f1f5f9;
      color: #64748b;
      border: 1px solid #e2e8f0;
    }
    .status-mag {
      background: #e0f2fe;
      color: #0369a1;
      border: 1px solid #bae6fd;
    }

    .legend-bar {
      font-size: 11px;
      color: #64748b;
      text-align: center;
      line-height: 1.4;
      max-width: 560px;
    }
  </style>
</head>
<body>

  
  <div class="controls-wrapper">
    <div class="controls">
      <button id="btnOn" class="btn" onclick="setField(true)">
        <span>🧲</span> Apply Field (B<sub>ext</sub> →)
      </button>
      <button id="btnOff" class="btn active" onclick="setField(false)">
        <span>⚪</span> Remove Field
      </button>
    </div>
  </div>

  
  <div class="grid">
    
    
    <div class="panel">
      <div class="panel-header">
        <div class="title">Soft Ferromagnet</div>
        <div class="sub">e.g., Soft Iron (Low Coercivity)</div>
      </div>
      <div class="svg-wrap">
        <svg viewBox="0 0 200 155" xmlns="http://www.w3.org/2000/svg">
          <defs>
            <marker id="arr-blue" viewBox="0 0 10 10" refX="5" refY="5" markerWidth="5" markerHeight="5" orient="auto">
              <path d="M 0 1.5 L 8 5 L 0 8.5 z" fill="#0284c7"/>
            </marker>
            <marker id="arr-muted" viewBox="0 0 10 10" refX="5" refY="5" markerWidth="5" markerHeight="5" orient="auto">
              <path d="M 0 1.5 L 8 5 L 0 8.5 z" fill="#64748b"/>
            </marker>
          </defs>

          
          <rect x="15" y="10" width="170" height="130" rx="8" fill="#f8fafc" stroke="#cbd5e1" stroke-width="2"/>

          
          <line id="softWallV" class="wall" x1="100" y1="10" x2="100" y2="140" stroke="#94a3b8" stroke-width="1.8" stroke-dasharray="4 3"/>
          <line id="softWallH" class="wall" x1="15" y1="75" x2="185" y2="75" stroke="#94a3b8" stroke-width="1.8" stroke-dasharray="4 3"/>

          
          
          <g transform="translate(57.5, 42.5)">
            <line id="sA1" class="arrow-line" x1="-16" y1="0" x2="16" y2="0" stroke="#64748b" stroke-width="3" marker-end="url(#arr-muted)" style="transform: rotate(-90deg);"/>
          </g>
          
          <g transform="translate(142.5, 42.5)">
            <line id="sA2" class="arrow-line" x1="-16" y1="0" x2="16" y2="0" stroke="#64748b" stroke-width="3" marker-end="url(#arr-muted)" style="transform: rotate(0deg);"/>
          </g>
          
          <g transform="translate(57.5, 107.5)">
            <line id="sA3" class="arrow-line" x1="-16" y1="0" x2="16" y2="0" stroke="#64748b" stroke-width="3" marker-end="url(#arr-muted)" style="transform: rotate(180deg);"/>
          </g>
          
          <g transform="translate(142.5, 107.5)">
            <line id="sA4" class="arrow-line" x1="-16" y1="0" x2="16" y2="0" stroke="#64748b" stroke-width="3" marker-end="url(#arr-muted)" style="transform: rotate(90deg);"/>
          </g>

          <text x="100" y="149" text-anchor="middle" font-size="9.5" fill="#64748b" font-weight="600">Smooth wall motion</text>
        </svg>
      </div>
      <div id="softBadge" class="status-badge status-off">Demagnetized (B = 0)</div>
    </div>

    
    <div class="panel">
      <div class="panel-header">
        <div class="title">Hard Ferromagnet</div>
        <div class="sub">e.g., NdFeB (High Coercivity)</div>
      </div>
      <div class="svg-wrap">
        <svg viewBox="0 0 200 155" xmlns="http://www.w3.org/2000/svg">
          
          <rect x="15" y="10" width="170" height="130" rx="8" fill="#f8fafc" stroke="#cbd5e1" stroke-width="2"/>

          
          <path d="M 15 42 Q 60 38, 95 65 T 140 100 T 185 108" fill="none" stroke="#94a3b8" stroke-width="1.5" stroke-dasharray="3 3" opacity="0.4"/>

          
          <g transform="translate(57.5, 42.5)">
            <line class="arrow-line" x1="-16" y1="0" x2="16" y2="0" stroke="#0284c7" stroke-width="3" marker-end="url(#arr-blue)"/>
          </g>
          <g transform="translate(142.5, 42.5)">
            <line class="arrow-line" x1="-16" y1="0" x2="16" y2="0" stroke="#0284c7" stroke-width="3" marker-end="url(#arr-blue)"/>
          </g>
          <g transform="translate(57.5, 107.5)">
            <line class="arrow-line" x1="-16" y1="0" x2="16" y2="0" stroke="#0284c7" stroke-width="3" marker-end="url(#arr-blue)"/>
          </g>
          <g transform="translate(142.5, 107.5)">
            <line class="arrow-line" x1="-16" y1="0" x2="16" y2="0" stroke="#0284c7" stroke-width="3" marker-end="url(#arr-blue)"/>
          </g>

          
          <g id="defects">
            <circle cx="60" cy="40" r="3.5" fill="#0f172a"/>
            <circle cx="95" cy="65" r="3.5" fill="#0f172a"/>
            <circle cx="140" cy="100" r="3.5" fill="#0f172a"/>
            <circle cx="100" cy="30" r="3.5" fill="#0f172a"/>
            <circle cx="55" cy="115" r="3.5" fill="#0f172a"/>
          </g>
          <text x="100" y="149" text-anchor="middle" font-size="9.5" fill="#0f172a" font-weight="600">● Pinning sites lock walls</text>
        </svg>
      </div>
      <div id="hardBadge" class="status-badge status-mag">Permanent Magnet (B &gt; 0)</div>
    </div>

  </div>

  <div class="legend-bar">
    Crystal defects (pinning sites) prevent domain walls from relaxing back, creating high remanence.
  </div>

  <script>
    let fieldOn = false;

    function setField(active) {
      fieldOn = active;
      document.getElementById('btnOn').classList.toggle('active', fieldOn);
      document.getElementById('btnOff').classList.toggle('active', !fieldOn);

      const sA1 = document.getElementById('sA1');
      const sA2 = document.getElementById('sA2');
      const sA3 = document.getElementById('sA3');
      const sA4 = document.getElementById('sA4');
      const softWallV = document.getElementById('softWallV');
      const softWallH = document.getElementById('softWallH');
      const softBadge = document.getElementById('softBadge');

      if (fieldOn) {
        // Soft magnet aligns with external field
        sA1.style.transform = 'rotate(0deg)';
        sA2.style.transform = 'rotate(0deg)';
        sA3.style.transform = 'rotate(0deg)';
        sA4.style.transform = 'rotate(0deg)';
        
        [sA1, sA2, sA3, sA4].forEach(el => {
          el.setAttribute('stroke', '#0284c7');
          el.setAttribute('marker-end', 'url(#arr-blue)');
        });
        
        softWallV.style.opacity = '0';
        softWallH.style.opacity = '0';
        softBadge.className = 'status-badge status-mag';
        softBadge.innerHTML = 'Magnetized (Aligned)';
      } else {
        // Soft magnet relaxes to cancel internal field (net zero magnetization)
        sA1.style.transform = 'rotate(-90deg)';
        sA2.style.transform = 'rotate(0deg)';
        sA3.style.transform = 'rotate(180deg)';
        sA4.style.transform = 'rotate(90deg)';

        [sA1, sA2, sA3, sA4].forEach(el => {
          el.setAttribute('stroke', '#64748b');
          el.setAttribute('marker-end', 'url(#arr-muted)');
        });

        softWallV.style.opacity = '1';
        softWallH.style.opacity = '1';
        softBadge.className = 'status-badge status-off';
        softBadge.innerHTML = 'Demagnetized (B = 0)';
      }
    }
  </script>
</body>
</html>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Atomic Magnetic Dipole</title>
  <style>
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    body {
      width: 100%;
      background: transparent;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
      color: #1e2945;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      padding: 10px 12px;
    }

    .diagram-wrap {
      width: 100%;
      max-width: 440px;
      display: flex;
      flex-direction: column;
      align-items: center;
    }

    svg {
      width: 100%;
      height: auto;
      max-height: 340px;
      display: block;
    }

    /* Controls bar */
    .controls {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-top: 6px;
    }

    .btn {
      background: #f1f5f9;
      border: 1px solid #cbd5e1;
      color: #1e2945;
      font-size: 13px;
      font-weight: 600;
      padding: 6px 16px;
      border-radius: 6px;
      cursor: pointer;
      display: inline-flex;
      align-items: center;
      gap: 6px;
      user-select: none;
      transition: background 0.15s, border-color 0.15s;
    }
    .btn:hover {
      background: #e2e8f0;
      border-color: #94a3b8;
    }
    .btn:active {
      background: #cbd5e1;
    }

    /* Pole labels */
    .pole-tag {
      font-size: 12px;
      font-weight: 700;
      letter-spacing: 0.5px;
    }

    /* Spin arrow pulse animation */
    @keyframes spinWiggle {
      0%, 100% { opacity: 0.85; stroke-width: 1.6; }
      50% { opacity: 1; stroke-width: 2.1; }
    }
    .spin-arrow {
      animation: spinWiggle 2s ease-in-out infinite;
    }
  </style>
</head>
<body>

<div class="diagram-wrap">
  <svg viewBox="0 25 400 280" aria-label="Atomic magnetic dipole diagram">
    <defs>
      
      <marker id="arrow-n" viewBox="0 0 10 10" refX="5" refY="5" markerWidth="6" markerHeight="6" orient="auto-start-reverse">
        <path d="M 0 1.5 L 10 5 L 0 8.5 z" fill="#dc2626" />
      </marker>
      <marker id="arrow-field" viewBox="0 0 10 10" refX="5" refY="5" markerWidth="5" markerHeight="5" orient="auto-start-reverse">
        <path d="M 0 2 L 8 5 L 0 8 z" fill="#94a3b8" />
      </marker>
      <marker id="arrow-orbit" viewBox="0 0 10 10" refX="5" refY="5" markerWidth="4.5" markerHeight="4.5" orient="auto-start-reverse">
        <path d="M 0 2 L 8 5 L 0 8 z" fill="#0284c7" />
      </marker>
      <marker id="arrow-spin" viewBox="0 0 10 10" refX="5" refY="5" markerWidth="4" markerHeight="4" orient="auto-start-reverse">
        <path d="M 0 2 L 8 5 L 0 8 z" fill="#0369a1" />
      </marker>

      
      <filter id="glow" x="-20%" y="-20%" width="140%" height="140%">
        <feGaussianBlur stdDeviation="2" result="blur" />
        <feComposite in="SourceGraphic" in2="blur" operator="over" />
      </filter>
    </defs>

    
    <g stroke="#cbd5e1" stroke-width="1.5" stroke-dasharray="4 4" fill="none" opacity="0.85">
      <path d="M 200 45 C 335 45, 360 285, 200 285" />
      <path d="M 200 45 C 65 45, 40 285, 200 285" />
      
      <path d="M 335 160 L 335 170" marker-end="url(#arrow-field)" stroke="#94a3b8" stroke-dasharray="none" />
      <path d="M 65 175 L 65 165" marker-end="url(#arrow-field)" stroke="#94a3b8" stroke-dasharray="none" />
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Magnetic Fields Around Current-Carrying Wires and Solenoids

Magnetic Fields and Lorentz Force on Moving Charges

Charged Particle Trajectories and Mass Spectrometry

Earth's Magnetic Field and Magnetospheric Shielding

Magnetic Force on a Current-Carrying Conductor: F = BIl sin θ

Magnetic Torque on Current Loops and DC Electric Motors

science

Magnetic Fields, Lorentz Force, and DC Motors

Fields: Forces That Act at a Distance

Magnetic Poles: Attraction and Repulsion Rules

Mapping Magnetic Field Lines Around Bar Magnets

Magnetic Field Strength and Flux Line Density

Magnetic Compasses and Earth's Magnetic Core

Uniform Magnetic Fields Between Opposite Poles

Permanent and Induced Magnetism

Magnetic Field Around a Current-Carrying Wire

Using the Right-Hand Grip Rule for Wire Fields

Factors Affecting Field Strength Around a Conductor

Solenoids: Creating Strong and Uniform Magnetic Fields

Electromagnets: Adding Iron Cores and Controlling Strength

Practical Applications of Electromagnets: Relays and Bells

Force on a Current-Carrying Conductor in a Magnetic Field

Finding Magnetic Force Direction with the Right-Hand Rule

Calculating Magnetic Force Using F = B × I × l

How Electric Motors and Loudspeakers Work

Electromagnetism and the Motor Effect

Force on a Current-Carrying Conductor

Using Fleming's Left-Hand Rule to Predict Force Direction

Rearranging the Magnetic Force Equation

Handling Unit Conversions in Magnetic Force Calculations

The Motor Effect and Magnetic Force Calculations

Structure and Operation of a Simple DC Electric Motor

The Role of the Split-Ring Commutator and Brushes

Factors Affecting the Speed and Direction of an Electric Motor

Loudspeakers and Headphones: Motor Effect in Sound

Exam-Style Questions on the Motor Effect and Motors

Electric Motors and Applications of the Motor Effect

Modelos cosmológicos: de los epiciclos al heliocentrismo

Ley de gravitación universal de Newton

Balanza de torsión de Cavendish y medición de la constante G

Concepto de campo gravitacional e intensidad g

Variación de la gravedad con la altitud, profundidad y latitud

Líneas de campo y superficies equipotenciales gravitacionales

Gravitación universal y campo gravitatorio

Campo gravitacional y leyes de Kepler

Energía potencial gravitacional a escala planetaria

Velocidad de escape y pozos de potencial gravitatorio

Dinámica de satélites artificiales en órbita circular

Fuerzas de marea e interacción gravitacional Tierra-Luna

Maniobras espaciales y transferencia orbital de Hohmann

Agujeros negros, radio de Schwarzschild y relatividad

Analogías estructurales entre campos gravitatorios y electrostáticos

Mecánica celeste y dinámica orbital

Campo eléctrico y líneas de fuerza

Campo eléctrico de distribuciones discretas de carga

Dipolo eléctrico y momento dipolar en campos uniformes

Flujo eléctrico y ley de Gauss conceptual

Conductores en equilibrio electrostático y blindaje

Campo eléctrico: distribuciones, ley de Gauss y conductores

Movimiento de partículas cargadas en campos eléctricos uniformes

Generador de Van de Graaff y ruptura dieléctrica del aire

Comparación cuantitativa entre campos gravitacionales y electrostáticos

Aplicaciones tecnológicas: fotocopiadoras, filtros y pintura

Fenómenos y aplicaciones electrostáticas

Pojęcie pola magnetycznego jako stanu przestrzeni wokół magnesów i poruszających się ładunków

Bieguny magnetyczne N i S — jednoimienne odpychanie i różnoimienne przyciąganie

Linie pola magnetycznego — definicja, zwrot, gęstość i charakter bezźródłowy

Rysowanie linii pola magnetycznego magnesu sztabkowego i podkowiastego

Pole magnetyczne jednorodne — linie równoległe o stałej gęstości w szczelinie magnesu

Doświadczenie: wizualizacja układu linii pola magnetycznego magnesów trwałych za pomocą opiłków żelaza

Igła magnetyczna jako próbnik pola — ustawianie się wzdłuż stycznej do linii pola

Wektor indukcji magnetycznej B jako podstawowa wielkość opisująca pole — jednostka tesla (T)

Typowe wartości indukcji magnetycznej — od pola Ziemi po magnesy MRI i pulsary

Pole magnetyczne i wektor indukcji magnetycznej

Energía potencial electrostática en sistemas de cargas

Potencial eléctrico y diferencia de potencial

Superficies equipotenciales y relación con el campo eléctrico

Capacitancia y almacenamiento de energía

Asociación de condensadores en serie y en paralelo

Potencial eléctrico y capacitancia

Electromagnetic Induction: Generating Electricity from Motion

Coulomb's Law: Force, Charge, and Distance

Calculating Electric Force Using Scientific Notation

How Charge and Distance Affect Electric Force

Comparing Electric and Gravitational Forces

Introduction to Electric Forces

Właściwości magnetyczne substancji — ferromagnetyki, paramagnetyki i diamagnetyki

Domeny magnetyczne (obszary Weissa) i proces namagnesowania ferromagnetyków

Temperatura Curie — przejście ferromagnetyka w paramagnetyk pod wpływem drgań cieplnych

Histereza magnetyczna — materiały magnetycznie miękkie (rdzenie) i twarde (magnesy stałe)

Magnesy neodymowe (NdFeB) — budowa, olbrzymia gęstość energii i zastosowania we współczesnej technice

Rysowanie linii pola dla złożonych konfiguracji przewodników i magnesów

Podsumowanie: źródła pola magnetycznego i reguły wyznaczania zwrotu linii

Właściwości magnetyczne materii i ferromagnetyzm

Electric and Magnetic Forces in Generators

Electric and Magnetic Forces in Motors

Electric and Magnetic Forces in Transformers

Identifying Electromagnetic Devices in Everyday Life

Electromagnetic Devices in Everyday Life

Doświadczenie Oersteda — odkrycie pola magnetycznego wokół przewodnika z prądem

Linie pola wokół prostoliniowego przewodnika z prądem — koncentryczne okręgi

Reguła prawej dłoni (reguła śruby prawoskrętnej) dla prostoliniowego przewodnika

Analiza proporcjonalności w polu przewodnika: wykres zależności B od natężenia I i odległości r

Linie pola magnetycznego przewodnika kołowego (pojedynczej pętli z prądem)

Pole magnetyczne zwojnicy (solenoidu) — analogia do magnesu sztabkowego

Reguła prawej dłoni dla zwojnicy — wyznaczanie biegunowości magnetycznej N i S

Czynniki wpływające na indukcję pola w zwojnicy — liczba zwojów n, natężenie I i długość l

Pole magnetyczne przewodników z prądem: przewód prostoliniowy, pętla i zwojnica

Budowa i działanie elektromagnesu — wielokrotne wzmocnienie pola przez rdzeń ze stali miękkiej

Doświadczenie: badanie i ilustrowanie linii pola wokół przewodnika prostoliniowego i zwojnicy

Zastosowania elektromagnesów — dźwigi elektromagnetyczne, przekaźniki i zamki magnetyczne

Oddziaływanie dwóch równoległych przewodników z prądem — przyciąganie i odpychanie

Historyczna i współczesna definicja jednostki natężenia prądu (amper) na bazie siły elektrodynamicznej

Złożone zadania maturalne z obliczania indukcji pola magnetycznego przewodników i zwojnic

Podsumowanie: magnetyzm materii, oddziaływanie przewodników i wizualizacja pól

Elektromagnesy, oddziaływanie przewodników z prądem i zastosowania

Campo magnético e imanes permanentes

Fuerza magnética sobre cargas en movimiento

Espectrometría de masas y aceleradores ciclotrón

Fuerza magnética sobre conductores con corriente: ley de Laplace

Torque sobre espiras y principio del motor eléctrico

Campos magnéticos generados por corrientes

Ley de Ampère y campo magnético en solenoides y toroides

Fuerza magnética entre conductores paralelos y definición del amperio

Campos magnéticos y fuerzas magnéticas

Magnesy trwałe — bieguny N i S, oddziaływanie dipolowe i brak monopoli magnetycznych

Doświadczenie Oersteda — powiązanie prądu elektrycznego z polem magnetycznym

Pole magnetyczne wokół przewodnika prostoliniowego — układ współśrodkowych okręgów

Reguła prawej dłoni (reguła śruby prawoskrętnej) dla przewodnika prostoliniowego

Pole magnetyczne magnesów trwałych i przewodnika prostoliniowego

Siła elektrodynamiczna — mechanizm powstawania i cechy wektora siły

Reguła lewej dłoni (reguła trzech palców) — wyznaczanie kierunku i zwrotu siły F_ed

Wzór na wartość siły elektrodynamicznej: F = I · l · B · sin(α)

Zależność siły elektrodynamicznej od kąta ustawienia przewodu względem linii pola

Doświadczenie: demonstracja siły elektrodynamicznej — ruch huśtawki przewodzącej w polu magnesu

Moment sił elektrodynamicznych działający na prostokątną ramkę z prądem: M = I · S · B · sin(θ)

Magnetyczny moment dipolowy pętli z prądem: m = I · S i orientacja dipola w polu

Siła elektrodynamiczna i moment sił w polu magnetycznym

Flujo magnético y ley de inducción de Faraday

Ley de Lenz y corrientes de Foucault (Eddy)

Generadores eléctricos y transformadores de voltaje

Autoinducción, inductores y energía del campo magnético

Ecuaciones de Maxwell y síntesis electromagnética

Espectro electromagnético y naturaleza de la luz

Campos de fuerza fundamentales: gravedad y electromagnetismo

Inducción electromagnética y síntesis de Maxwell

Pole magnetyczne kołowego przewodnika z prądem (ramki/zwoju)

Pole magnetyczne długiej zwojnicy (solenoidu) — jednorodność pola wewnątrz cewki

Reguła prawej dłoni dla zwojnicy — wyznaczanie biegunów magnetycznych cewki

Elektromagnes — wzmacnianie pola magnetycznego za pomocą rdzenia ferromagnetycznego

Zastosowania elektromagnesów w technice — przekaźniki, zamki elektromagnetyczne i kolej Maglev

Superpozycja pól magnetycznych — wektorowe dodawanie indukcji od wielu źródeł

Pole magnetyczne zwojnic, elektromagnesy i superpozycja pól

Budowa i zasada działania silnika prądu stałego — rola komutatora i szczotek

Przemiany energii i sprawność silnika elektrycznego — moc mechaniczna i straty cieplne

Mierniki magnetoelektryczne — cewka obrotowa w polu magnesu i sprężyna zwrotna

Głośnik elektrodynamiczny — przetwarzanie sygnału elektrycznego AC na falę akustyczną

Silniki bezszczotkowe BLDC i silniki krokowe — elektroniczna komutacja w robotyce i pojazdach EV

Zadania rachunkowe: równowaga pręta z prądem na szynach w polu magnetycznym

Waga prądowa — precyzyjny laboratoryjny pomiar wektora indukcji magnetycznej B

Podsumowanie: siła elektrodynamiczna w fizyce i technice napędowej

Silniki elektryczne i elektromechaniczne zastosowania magnetyzmu

Oddziaływanie pola magnetycznego na ładunek w ruchu — wprowadzenie do siły Lorentza

Reguła lewej dłoni dla siły Lorentza — rozróżnienie cząstek dodatnich (protony) i ujemnych (elektrony)

Wzór na wartość siły magnetycznej Lorentza: F_L = |q| · v · B · sin(α)

Ruch cząstki wzdłuż linii pola (α = 0° lub 180°) — brak siły magnetycznej

Ruch cząstki prostopadle do linii pola (α = 90°) — ruch po okręgu i promień r = m · v / (|q| · B)

Okres obiegu i częstotliwość cyklotronowa: T = 2πm / (|q|B) — niezależność od prędkości cząstki

Ruch cząstki pod kątem ostrym do linii pola — tor śrubowy (helisa)

Zerowa praca siły Lorentza (W = 0) — zmiana wyłącznie kierunku prędkości bez zmiany energii kinetycznej

Zastosowania w fizyce jądrowej: cyklotron, synchrotron i zakrzywianie wiązek w LHC

Spektrometr mas — filtr prędkości i rozdzielanie jonów o różnym stosunku masy do ładunku

Siła Lorentza i ruch naładowanych cząstek w polu magnetycznym

Wektor indukcji magnetycznej B — podstawowa wielkość opisująca pole magnetyczne

Jednostka indukcji magnetycznej tesla (T) — definicja 1 T = 1 N / (A · m)

Strumień indukcji magnetycznej Φ = B · S · cos(α) i jednostka weber (Wb)

Wektor indukcji i strumień pola magnetycznego

Evidence for Fields Between Non-Contacting Objects

Generators, Motors, and Transformers in Everyday Life

Identifying Electromagnetic Devices Around Us

Charge Conservation During Conduction

Charge Conservation During Induction

Charge Separation by Polarization

Investigating Charge with Electroscopes and Van de Graaff Generators

Electromagnetic Devices and Charge Conservation

Mechanizm geodynamo — powstawanie pola magnetycznego w płynnym jądrze Ziemi

Magnetosfera Ziemi jako tarcza ochronna przed wiatrem słonecznym i promieniowaniem kosmicznym

Pasy radiacyjne Van Allena — pułapkowanie naładowanych cząstek w ziemskim polu magnetycznym

Zorza polarna (aurora borealis i australis) — emisja światła przez wzbudzone atomy azotu i tlenu

Burze geomagnetyczne — koronalne wyrzuty masy (CME) i ich wpływ na sieci przesyłowe i satelity GPS

Inwersje pola magnetycznego Ziemi i paleomagnetyzm w spreadingu dna oceanicznego

OGS.12.PS3.6

Aligned learning resources

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