EETC Circuit Design & Troubleshooting 3

Question 1

A class-A amplifier operates with the transistor conducting for what portion of the input signal cycle?

Accepted Answer

100%

Answer

In class-A operation, the transistor is biased to conduct continuously throughout the entire 360° of the input signal cycle.

Question 2

What does a megohmmeter (megger) primarily measure in electrical troubleshooting?

Accepted Answer

Insulation resistance between conductors and ground

Answer

A megohmmeter applies high DC voltage (typically 500–5000V) to measure insulation resistance, detecting degraded or failed insulation.

Question 3

In a full-wave bridge rectifier, how many diodes conduct simultaneously during each half-cycle?

Accepted Answer

2

Answer

During each half-cycle of a bridge rectifier, current flows through exactly two diodes—one on the top and one on the bottom of the bridge.

Question 4

When designing a PCB for high-frequency circuits, why should ground planes be used?

Accepted Answer

To reduce electromagnetic interference and provide a low-inductance return path

Answer

Ground planes provide a low-impedance, low-inductance return path for currents and reduce EMI by shielding signal traces.

Question 5

A technician notices that a voltage regulator IC is very hot to the touch even with a minimal load. What is the most likely cause?

Accepted Answer

Excessive input-to-output voltage differential across the regulator

Answer

Linear regulators dissipate power equal to (Vin − Vout) × Iload, so a large input-to-output differential causes high heat even at low currents.

(EETC) Electrical Technician Certification Practice Test