Govt. Exams
Entrance Exams
Nodal analysis uses Kirchhoff's current law (KCL) at each node to find node voltages, with one node taken as reference (ground)
For sinusoidal current I = Im sin(ωt + φ), IRMS = Im/√2 = 5/√2 = 3.54 A
Time constant τ = L/R = 0.5/100 = 0.005 s = 5 ms
Mesh analysis applies Kirchhoff's voltage law (KVL) around each independent mesh loop in the circuit
For parallel resistors: 1/Req = 1/R + 1/R = 2/R. Therefore, Req = R/2
In a balanced three-phase system, VL = √3 × Vph. Therefore, Vph = VL/√3 = 400/√3 = 400/1.732 = 230.9 V
Energy stored in capacitor = (1/2)CV² = (1/2) × 100×10⁻⁶ × 200² = 0.5 × 100×10⁻⁶ × 40000 = 2 J
Thevenin equivalent voltage is the open-circuit voltage measured across the two terminals when the load is removed from the circuit.
An ideal voltage source maintains constant voltage regardless of load, which requires zero internal resistance.
In a purely inductive circuit, current lags voltage by 90° due to self-inductance effects.
