ISCET Component-Level Troubleshooting 4

Question 1

A technician uses the half-splitting (divide and conquer) method. What is the primary advantage of this technique?

Accepted Answer

It minimizes the number of tests needed to isolate a fault

Answer

Half-splitting divides the circuit at its midpoint each test, logarithmically reducing the number of checks needed to isolate a fault.

Question 2

Which failure mode of an electrolytic capacitor is indicated by visible bulging or electrolyte leakage?

Accepted Answer

Catastrophic failure due to overvoltage or reversed polarity

Answer

Bulging and leakage result from excessive internal pressure caused by overvoltage, reverse polarity installation, or thermal stress leading to catastrophic failure.

Question 3

When checking a transformer for a shorted winding, a technician should measure:

Accepted Answer

Both B and C

Answer

Shorted windings reduce DC resistance below specification, and a megohmmeter check confirms inter-winding insulation integrity; both tests together give a complete picture.

Question 4

A PNP transistor has its emitter at +12 V, base at +11.3 V, and collector at +6 V. The transistor is:

Accepted Answer

In the active region

Answer

VEB ≈ 0.7 V forward biases the emitter-base junction, and VEC = 6 V provides adequate collector voltage, placing it in the active region.

Question 5

What does high ESR (Equivalent Series Resistance) in an electrolytic capacitor cause in a switching power supply?

Accepted Answer

Excessive output ripple and overheating of the capacitor

Answer

High ESR prevents the capacitor from effectively filtering ripple, increasing output ripple voltage and generating heat within the capacitor.

(ISCET) International Society of Certified Electronics Technicians Practice Test

(ISCET) International Society of Certified Electronics Technicians Practice Test

ISCET Component-Level Troubleshooting 4