Electrical Engineering / Subcategory
Circuit Analysis
Circuit analysis calculators and formulas for Kirchhoff's laws, series/parallel networks, and voltage dividers. Covers current divider, equivalent resistance, and Thevenin/Norton equivalent circuit calculations.
20Formulas
All levels Difficulty
Updated Jul 2026
← All Electrical Engineering (151) Circuit Analysis (20)
Fundamental
Wheatstone Bridge Balance Condition
R₁/R₂ = R₃/R₄
Fundamental
Capacitor Charge Relation
Q = C·V
Fundamental
Energy Stored in an Inductor
E = ½L·I²
Fundamental
Energy Stored in a Capacitor
E = ½C·V²
Fundamental
Inductor Current Growth
I(t) = (V/R)(1 − e^(−tR/L))
Fundamental
Capacitor Discharging Voltage
V(t) = V₀·e^(−t/RC)
Fundamental
Capacitor Charging Voltage
V(t) = V₀(1 − e^(−t/RC))
Fundamental
RL Time Constant
τ = L / R
Fundamental
RC Time Constant
τ = R·C
Fundamental
Current Divider Rule
I_x = I_in · (R_T / R_x)
Fundamental
Delta-to-Wye Transformation
R_a = (R_ab·R_ca) / (R_ab+R_bc+R_ca)
Fundamental
Millman's Theorem
V = (ΣI_k) / (ΣG_k)
Fundamental
Maximum Power Transfer Theorem
P_max occurs when R_L = R_TH
Fundamental
Thevenin's Theorem Equivalent Resistance
R_TH = V_OC / I_SC
Fundamental
Norton's Theorem Equivalent Current
I_N = I_SC
Fundamental
Voltage Divider Rule
V_x = V_in · (R_x / R_T)
Fundamental
Parallel Resistance
1/R_T = 1/R₁ + 1/R₂
Fundamental
Series Resistance
R_T = R₁ + R₂ + ... + Rₙ
Fundamental
Kirchhoff's Current Law
ΣI_in = ΣI_out
Fundamental
Kirchhoff's Voltage Law
ΣV = 0