The most common unit of energy in Biology is calories. A calorie is a unit of energy, require to raise 1 kilogram of water to 4.1868 joules.

Power factor is defined as the ratio of real power over total power. Total power is the vector sum of real and reactive power.

The power of congress to declare war and raise an army or navy is an expressed power.

ratio between true power and apparent power is called the power factor for a circuit

Power factor =true power/apparent power

also we conclude PF=power dissipated / actual power in pure resistive circuit

if total resistance is made zero power factor will be zero

Power input connector, or just power connector