Physics — Labelled DC Circuit (Series–Parallel)

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    {
      "id": "ci-batt",
      "type": "battery",
      "label": "B1 = 12.0 V — ideal DC supply, no internal resistance; P(B1) = 0.48 W; Z(B1) = 300 Ω",
      "x": 60,
      "y": 60,
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      "fill": "#dbeafe",
      "stroke": "#1d4ed8"
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    {
      "id": "ci-sw",
      "type": "switch",
      "label": "SW1 — SPST switch, shown closed",
      "x": 340,
      "y": 60,
      "width": 240,
      "height": 117,
      "fill": "#fef3c7",
      "stroke": "#b45309"
    },
    {
      "id": "ci-fuse",
      "type": "fuse",
      "label": "F1 — 1 A quick-blow fuse, intact (a closed switch to the model)",
      "x": 620,
      "y": 60,
      "width": 240,
      "height": 117,
      "fill": "#fef3c7",
      "stroke": "#b45309"
    },
    {
      "id": "ci-am",
      "type": "gauge-chart",
      "label": "A1 — ammeter in series: I(A1) = 40.0 mA",
      "x": 900,
      "y": 60,
      "width": 240,
      "height": 117,
      "fill": "#fce7f3",
      "stroke": "#be185d"
    },
    {
      "id": "ci-r1",
      "type": "resistor",
      "label": "R1 = 100 Ω; V(R1) = 4.0 V; I(R1) = 40.0 mA",
      "x": 1180,
      "y": 60,
      "width": 240,
      "height": 117,
      "fill": "#ede9fe",
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    },
    {
      "id": "ci-gnd",
      "type": "ground",
      "label": "0 V reference — chassis earth at the supply negative",
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      "y": 235,
      "width": 240,
      "height": 117,
      "fill": "#dbeafe",
      "stroke": "#1d4ed8"
    },
    {
      "id": "ci-vm",
      "type": "gauge-chart",
      "label": "V1 — voltmeter across A–B: V(V1) = 8.0 V",
      "x": 340,
      "y": 235,
      "width": 240,
      "height": 117,
      "fill": "#fce7f3",
      "stroke": "#be185d"
    },
    {
      "id": "ci-c1",
      "type": "capacitor",
      "label": "C1 = 100 µF across A–B (decoupling); V(C1) = 8.0 V; Q(C1) = 0.80 mC",
      "x": 620,
      "y": 235,
      "width": 240,
      "height": 117,
      "fill": "#ede9fe",
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    },
    {
      "id": "ci-r2",
      "type": "resistor",
      "label": "R2 = 300 Ω; I(R2) = 26.7 mA; P(R2) = 0.213 W",
      "x": 900,
      "y": 235,
      "width": 240,
      "height": 117,
      "fill": "#ede9fe",
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    },
    {
      "id": "ci-na",
      "type": "ellipse",
      "label": "Node A: V(A) = 8.0 V above the 0 V rail; Vth(A) = 8.0 V; Rth(A) = 66.7 Ω",
      "x": 1180,
      "y": 235,
      "width": 240,
      "height": 117,
      "fill": "#e0f2fe",
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    },
    {
      "id": "ci-work",
      "type": "note",
      "label": "The parallel pair R2‖R3 is 200 Ω and the supply sees 300 Ω in all: I(B1) = 40.0 mA and P(B1) = 0.48 W.",
      "x": 60,
      "y": 410,
      "width": 240,
      "height": 117,
      "fill": "#fef9c3",
      "stroke": "#ca8a04"
    },
    {
      "id": "ci-kcl",
      "type": "note",
      "label": "Kirchhoff's current law at node A: 26.7 mA and 13.3 mA rejoin as I(B1) = 40.0 mA. Voltage law round the outer loop: V(R1) = 4.0 V plus V(A) = 8.0 V makes the 12.0 V of the supply.",
      "x": 340,
      "y": 410,
      "width": 240,
      "height": 117,
      "fill": "#fef9c3",
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    },
    {
      "id": "ci-nb",
      "type": "ellipse",
      "label": "Node B — the 0 V return rail",
      "x": 620,
      "y": 410,
      "width": 240,
      "height": 117,
      "fill": "#e0f2fe",
      "stroke": "#0369a1"
    },
    {
      "id": "ci-r3",
      "type": "resistor",
      "label": "R3 = 600 Ω; I(R3) = 13.3 mA; P(R3) = 0.107 W",
      "x": 900,
      "y": 410,
      "width": 240,
      "height": 117,
      "fill": "#ede9fe",
      "stroke": "#6d28d9"
    },
    {
      "id": "ci-cap",
      "type": "note",
      "label": "In the steady state no current flows through C1 — it holds V(C1) = 8.0 V across A–B and stores Q(C1) = 0.80 mC.",
      "x": 1180,
      "y": 410,
      "width": 240,
      "height": 117,
      "fill": "#fef9c3",
      "stroke": "#ca8a04"
    }
  ],
  "edges": [
    {
      "id": "ci-e1",
      "source": "ci-gnd",
      "target": "ci-batt",
      "label": "0 V reference"
    },
    {
      "id": "ci-e2",
      "source": "ci-batt",
      "target": "ci-sw",
      "label": "+12.0 V rail"
    },
    {
      "id": "ci-e3",
      "source": "ci-sw",
      "target": "ci-fuse"
    },
    {
      "id": "ci-e4",
      "source": "ci-fuse",
      "target": "ci-am"
    },
    {
      "id": "ci-e5",
      "source": "ci-am",
      "target": "ci-r1",
      "label": "40.0 mA"
    },
    {
      "id": "ci-e6",
      "source": "ci-r1",
      "target": "ci-na",
      "label": "rail falls 12.0 → 8.0 V"
    },
    {
      "id": "ci-e7",
      "source": "ci-na",
      "target": "ci-r2",
      "label": "8.0 V across the branch"
    },
    {
      "id": "ci-e8",
      "source": "ci-na",
      "target": "ci-r3",
      "label": "8.0 V across the branch"
    },
    {
      "id": "ci-e9",
      "source": "ci-r2",
      "target": "ci-nb",
      "label": "26.7 mA"
    },
    {
      "id": "ci-e10",
      "source": "ci-r3",
      "target": "ci-nb",
      "label": "13.3 mA"
    },
    {
      "id": "ci-e11",
      "source": "ci-nb",
      "target": "ci-gnd",
      "label": "40.0 mA returns"
    },
    {
      "id": "ci-e12",
      "source": "ci-na",
      "target": "ci-c1",
      "label": "no steady-state current",
      "style": "dotted",
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    },
    {
      "id": "ci-e13",
      "source": "ci-c1",
      "target": "ci-nb",
      "style": "dotted",
      "arrowEnd": false
    },
    {
      "id": "ci-e14",
      "source": "ci-na",
      "target": "ci-vm",
      "label": "sense +",
      "style": "dotted",
      "arrowEnd": false
    },
    {
      "id": "ci-e15",
      "source": "ci-nb",
      "target": "ci-vm",
      "label": "sense −",
      "style": "dotted",
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