AEMT Sandbox - Association of Electrical and Mechanical Trades

Engineering Formulae
Quantity Symbol Unit Symbol Example
apparent power S Voltage x Current VA 120kVA (1000 x V x I )
current I Ampere A  
efficiency η per unit   0.95 (i.e. 95%)
frequency f Hertz Hz 50 Hz
poles p number   2 pole, 4 pole
pole pairs pp number   4 pole is 2 pp
active power P Watt W kW = 1000 x W
power, input Pin Watt W  
power, output Pout Watt W  
power factor pf per unit   0.86
reactive power Q Voltage x Current reactive var  
slip s per unit    
speed N revs per minute   Not SI unit
torque T Newton . metre Nm  
voltage V Volt V  


Quantity DC AC 1 Phase AC 3 Phase
Current (I)
Power Factor  


Quantity Formula
Fan load power
Fan load power

Ohm's Law

(Resistive circuits)

Power (kW)
Power (Hp)
Power Factor
Pump load power (Hp)
Pump load power (kW)
Slip, s,  (p.u.)
Slip,  (%)
Synchronous speed, NS,  (rpm)
Torque (N.m)
Torque (lb.ft)
Training & Accreditation
News & AEMT Publications