Electrical Contractor Electrical Theory & Fundamentals Flashcards
6 cards from real Licensed Electrical Contractor practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Electrical Contractor Electrical Theory & Fundamentals flashcards as text
A 240-volt circuit supplies a 5,000-watt electric heater. What is the current draw of the heater?
Answer: 20.83 amps
Using P = V × I, the current is 5,000 ÷ 240 = 20.83 amps.
What is the total resistance of three 30-ohm resistors connected in parallel?
Answer: 10 ohms
For identical resistors in parallel, total resistance equals one resistor's value divided by the number of resistors: 30 ÷ 3 = 10 ohms.
Which type of electrical current periodically reverses direction?
Answer: Alternating current (AC)
Alternating current reverses its direction of flow at regular intervals, typically 60 times per second in the US.
In a series circuit with a 120-volt source and two equal resistors, what is the voltage drop across each resistor?
Answer: 60 volts
In a series circuit, voltage divides proportionally, so two equal resistors each drop half the source voltage: 120 ÷ 2 = 60 volts.
What is the power factor of a purely resistive AC circuit?
Answer: 1.0
A purely resistive load has voltage and current perfectly in phase, resulting in a power factor of 1.0 (unity).
A conductor has a resistance of 4 ohms and carries 8 amps of current. How much power is dissipated as heat?
Answer: 256 watts
Using P = I² × R, the power is 8² × 4 = 64 × 4 = 256 watts.