Electrician Electrical Theory and Math 2

Question 1

In a parallel circuit, what happens to total resistance as more resistors are added?

Accepted Answer

It decreases

Answer

Adding more resistors in parallel provides additional paths for current, reducing overall resistance.

Question 2

What is the frequency of standard AC power in the United States?

Accepted Answer

60 Hz

Answer

The US electrical grid operates at 60 Hz, meaning AC voltage completes 60 cycles per second.

Question 3

What is the RMS voltage of US standard household current if the peak voltage is approximately 170V?

Accepted Answer

120V

Answer

RMS voltage equals peak voltage multiplied by 0.707, so 170 × 0.707 ≈ 120V.

Question 4

What is the impedance of a circuit with 8 ohms resistance and 6 ohms reactance?

Accepted Answer

10 ohms

Answer

Impedance Z = √(R² + X²) = √(64 + 36) = √100 = 10 ohms.

Question 5

Which of the following best describes inductance in an electrical circuit?

Accepted Answer

Opposition to change in current

Answer

Inductance is the property of a conductor that opposes changes in current flow, measured in henries.

Electrician Practice Test