Electrical Engineering Subjects
"Future REE! Ito na ang core ng profession natin - Circuits, Machines, Power Systems, and the Philippine Electrical Code. Master these to become a licensed Electrical Engineer!"
REE Challenge
Core EE Subjects - Circuits, Machines, Power, and PEC!
1. Circuit Analysis
Ohm's Law
V = I x R
The most fundamental law in EE!
Kirchhoff's Laws
- KCL: Sum of currents at a node = 0
- KVL: Sum of voltages around a loop = 0
Series and Parallel
- Series R: R_total = R1 + R2 + R3...
- Parallel R: 1/R_total = 1/R1 + 1/R2 + 1/R3...
- Series C: 1/C_total = 1/C1 + 1/C2...
- Parallel C: C_total = C1 + C2 + C3...
2. AC Circuit Analysis
Impedance
- Z_R = R (Resistor)
- Z_L = jwL = XL angle 90deg (Inductor)
- Z_C = 1/jwC = XC angle -90deg (Capacitor)
Power Triangle
- S = V x I* (Apparent power, VA)
- P = VI cos(theta) (Real power, W)
- Q = VI sin(theta) (Reactive power, VAR)
- PF = cos(theta) = P/S
Resonance
f_r = 1 / (2 x pi x sqrt(LC))
At resonance: XL = XC, Z = R (minimum)
3. Electrical Machines
Transformers
- V1/V2 = N1/N2 = I2/I1 = a (turns ratio)
- Step-up: N2 > N1
- Step-down: N2 < N1
- Efficiency: eta = Pout / Pin x 100%
DC Motors
- Back EMF: Eb = V - IaRa
- Torque: T = k x phi x Ia
- Speed: N = (V - IaRa) / (k x phi)
Induction Motors
- Sync speed: Ns = 120f / P
- Slip: s = (Ns - Nr) / Ns
- Rotor frequency: fr = s x f
4. Power Systems
Three-Phase Systems
- Wye: V_L = sqrt(3) x V_ph, I_L = I_ph
- Delta: V_L = V_ph, I_L = sqrt(3) x I_ph
- P_3ph = sqrt(3) x VL x IL x cos(theta)
Per-Unit System
pu = Actual / Base
Z_base = V_base2 / S_base
5. Philippine Electrical Code (PEC)
Grounding
- Equipment grounding: Safety
- System grounding: Voltage stabilization
- Ground resistance: Less than 25 ohms
Wire Sizing
- Based on ampacity tables
- Consider ambient temperature derating
- Voltage drop: Max 3% for branch, 5% total
Protection
- OCPD (Overcurrent Protection Device)
- Circuit breakers and fuses
- GFCI for wet locations
REE Pro Tips - EE Subjects
- - For AC: Always convert to phasor form first
- - Three-phase: Remember sqrt(3) = 1.732
- - Sync speed: Ns = 120f/P (memorize this!)
- - PEC: Know the grounding requirements
- - Transformer losses: Core (constant) + Copper (variable)
Test Your Knowledge! 🧠
Ready ka na ba? Take the practice quiz for Electrical Engineering Subjects to reinforce what you just learned.
Start Practice Quiz 📝