Kirchhoff’s Voltage Law (KVL) — Loop Flow
Fundamental Laws
Author: Mark Higgins
© Mark Anthony Higgins 11 October 2025
Revised Date: 19 April 2026
Kirchhoff’s Voltage Law (KVL) describes the conservation of energy within a closed electrical loop. It states that the total sum of voltage gains and drops around any complete path must equal zero, ensuring that energy is neither created nor lost within the system.
In physical terms, KVL reflects how energy supplied by sources is fully accounted for by the energy used or dissipated across components. Within a structured flow perspective, it is understood as a global conservation rule—one that enforces balance across entire loops and ensures system coherence over complete paths.
This flow reframes KVL as a constraint that governs how voltage is distributed within closed circuits. It ensures that all potential differences resolve across a loop, defining how energy is transferred, shared, and dissipated throughout the system.
By viewing KVL as a structured loop flow constraint, circuits can be analysed as complete energy systems where all gains and losses are accounted for. This perspective enables deeper understanding of circuit behaviour, from simple loops to complex networks.
This page includes an executable teaching flow that can run inside any modern AI system (ChatGPT, Google AI, Claude, and others). It is designed to teach the concept interactively and adapt to your level of understanding.
The more you interact (ask questions, answer checks, request examples), the better the system adapts to you.
Flow: KirchhoffsVoltageLaw_LoopFlow_v1_0
Purpose:
Model Kirchhoff’s Voltage Law as the conservation of energy around a closed electrical loop, enabling structured teaching of how voltage rises and drops balance within a circuit path.
System:
S = (I, R, B, K)
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Teaching Directive
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Execution_Mode:
Teaching
Audience:
Beginner to Intermediate learner
Teaching_Flow:
Explain → Visualise → Formalise → Apply
Instruction:
- Begin with intuitive explanation of a loop as a complete closed path through a circuit
- Explain that energy gained from sources must equal energy lost across components
- Introduce the rule that the algebraic sum of voltages around a closed loop is zero
- Relate KVL to voltage rises and drops in simple series circuits
- Reinforce with loop diagrams and worked voltage balance examples
Constraints:
H = ∅
Clarity before formalism
Goal:
Student understands that:
- voltage is conserved around a closed loop
- source voltage is balanced by component voltage drops
- KVL governs energy balance in circuit paths
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State
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I = {
loop_identifier,
source_voltages,
component_voltage_drops,
path_configuration,
loop_direction,
polarity_assignments,
energy_balance_state,
conductive_path,
time_state
}
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Rules
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R = {
detect_closed_loop,
identify_voltage_rises,
identify_voltage_drops,
assign_loop_direction,
sum_algebraic_voltages,
evaluate_loop_balance,
update_energy_distribution
}
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Boundaries
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B = {
valid_closed_loop_required,
voltage_values_defined,
polarity_assignments_consistent,
loop_direction_defined,
conductive_path_required,
no_unphysical_energy_gain_or_loss
}
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Invariants
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K = {
algebraic_sum_of_voltages_around_closed_loop_equals_zero,
ΣV_loop = 0,
total_voltage_rises_equal_total_voltage_drops,
energy_is_conserved_around_loop,
voltage_balance_depends_on_polarity_and_traversal_direction,
no_net_energy_creation_in_ideal_loop_analysis
}
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Execution
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E_t = expand(I, R)
V_t = {
x ∈ E_t | x satisfies (B ∧ K)
}
Selection:
x* = argmax_(x ∈ V_t) P(x | I, R, B, K)
Update:
I_(t+1) = update(I_t, x*)
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Output
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O = loop_voltage_balance | (B, K)
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Failure Condition
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V_t = ∅ ⇒ O = FAIL
Meaning:
If no valid closed loop, polarity structure, or voltage balance condition can be established, no coherent loop voltage relation can be evaluated.
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Interpretation
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Kirchhoff’s Voltage Law defines the conservation of energy around a closed circuit loop. As charge moves around the loop, the total energy gained from sources must equal the total energy lost across resistive or other circuit elements.
This means the algebraic sum of all voltage rises and drops around the loop is zero. KVL therefore governs how source voltages and component voltage drops balance within a complete circuit path.
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Core Relations
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ΣV_loop = 0
Total voltage rises = Total voltage drops
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Derived Relations
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V_source - V1 - V2 - ... - Vn = 0
V_source = V1 + V2 + ... + Vn
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Teaching Outcome
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Student can:
- Understand a loop as a complete closed path in a circuit
- Apply KVL to calculate unknown voltages
- Explain voltage drops across components in series circuits
- Relate KVL to conservation of energy
- Use polarity and direction consistently in loop analysisVoltage represents the difference in electrical potential between two points—the driving force behind all circuit behaviour.
This section frames voltage as a structured gradient, showing how energy conditions are established, compared, and measured across a system.
Current is the realised movement of charge through a conductive path—the observable expression of system activity.
Here, current is explored as a continuous flow, revealing how charge propagates, how paths constrain movement, and how flow defines system dynamics.
Resistance defines how a system constrains and shapes the movement of charge.
This section examines resistance as an opposition flow—where material structure, geometry, and conditions regulate how easily current can pass.
Power captures the rate at which energy is transferred within a system.
This section explores how voltage and current combine to produce real energy flow, revealing how systems do work, dissipate energy, and operate over time.