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S1-Q4.) The difference between alternating and direct current is that AC is

a.) *bi-directional
Correct. Alternating current first travels in the positive direction and then
reverses direction to travel in the negative direction.
b.) Always constant
Direct current is always constant, alternating current changes its value with each cycle.
c.) Safer
Alternating current is generally not safer than direct current. 60Hz is especially deadly since
it causes the heart to fibrillate and fall into cardiac arrest. As little as 20 mA can cause death.
d.) Faster
This answer has no meaning as related to alternating vs. direct current.

S1-Q5.) Reactive Power in an AC circuit is termed

a.) W
This is Real Power, or Watts and is depicted on the X-axis.
b.) VA
This is Apparent Power, or Volt*Amps and is depicted between the X and Y Axis.
c.) *VAR
Correct. This is Reactive Power, or Volt*Amp*Reactance and is depicted on the Y axis.
d.) Capacitive load
Not a type of Power.

S1-Q6.) Which of the following determines total power in a series circuit?

a.) *Source voltage times the current
Correct. Current is always the same throughout a series circuit and the source
voltage will be completely used up by the devices that current flows through. Since
they are in series, the current flows through all the devices and these devices
consume all the power.
b.) Total voltage applied to the circuit
This answer does not take into account all of the variables in the power calculation P= I*E.
c.) Current flowing through a switch
A switch has little to no resistance. Without resistance, there would be no voltage drop. Without
voltage drop there is no power consumed.
d.) Average of the wattage consumed by each resistor
This would only calculate the average power consumed by individual devices.

S1-Q7.) The formula for calculating power factor in a three phase circuit is

a.) Watts*1.732*Volts
This answer does not take Amps into consideration.
b.) *Watts/(Volts*Amps*1.732)
Correct. To determine Power Factor the apparent power (Volts*Amps) must be
multiplied by √(3) or 1.732. Next the real power, or wattage is divided by that product.
c.) Volts/Amps*1.723
Wattage is not considered in this equation and wattage is a component of Power Factor.
d.) Watts/(Volts*Amps*1.414)
1.414 is √(2) and used to calculate the peak or rms power, not power factor.

EGSA Apprentice Certification Program Study Guide - Page 58