Free IEM Electronic Components & Troubleshooting Questions and Answers — Questions and Answers
Question 1: What is the main function of a resistor in an electronic circuit?
- Store electrical charge
- Amplify signals
- Limit current flow (Correct answer)
- Convert AC to DC
Correct answer: Limit current flow
A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. Its primary function is to oppose or limit the flow of electric current, protecting other components, setting voltage levels, and controlling circuit behavior.
Question 2: Which tool is commonly used to measure voltage in a circuit?
- Oscilloscope
- Multimeter (Correct answer)
- Soldering iron
- Function generator
Correct answer: Multimeter
A multimeter is a versatile electronic measuring instrument that combines several measurement functions in one unit. It is specifically designed to measure voltage (volts), current (amperes), and resistance (ohms). Technicians commonly use it to diagnose electrical issues by checking voltage levels in various parts of a circuit.
Question 3: What is the likely cause of a capacitor bulging or leaking?
- High-frequency operation
- Incorrect polarity or overvoltage (Correct answer)
- Low temperature environment
- Exposure to light
Correct answer: Incorrect polarity or overvoltage
Capacitors can bulge or leak due to internal pressure buildup, often caused by incorrect polarity or overvoltage. Applying voltage in reverse polarity or exceeding the capacitor's rated voltage can damage the dielectric material and electrolyte. This leads to overheating, gas generation, and eventual physical deformation or rupture of the capacitor casing.
Question 4: Which of the following is a sign of a faulty diode?
- It reads low resistance in both directions (Correct answer)
- It emits a clicking noise
- It stores high voltage
- It produces AC signals
Correct answer: It reads low resistance in both directions
A healthy diode acts as a one-way valve for current, exhibiting low resistance in one direction (forward bias) and very high resistance in the other (reverse bias). If a diode reads low resistance in both directions, it indicates an internal short circuit. This means the diode has failed and can no longer block current effectively, allowing it to flow freely in both directions.
Question 5: What is the first step in safely troubleshooting an electronic circuit?
- Measure all resistor values
- Test diodes for continuity
- Power off and discharge capacitors (Correct answer)
- Replace the PCB
Correct answer: Power off and discharge capacitors
Before troubleshooting any electronic circuit, the first and most crucial safety step is to power off the equipment and discharge any capacitors. Capacitors can store dangerous amounts of electrical energy even after the power supply is disconnected. Discharging them prevents accidental electric shock and protects both the technician and the equipment from damage during subsequent testing.
Free IEM Electronic Components & Troubleshooting Questions and Answers
What is the main function of a resistor in an electronic circuit?