Questions – Answers
Electrical and Electronics Engineering Interview Questions and Answers
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How Do GFCI and Standard Breakers Respond to Ground Faults?
How Does a GFCI Breaker Protect Us in Case of a Fault, Compared to Standard Breakers? An ordinary circuit breaker in the main panel for household appliances protects only in…
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What Happens if the Neutral is Lost in the Main or Subpanel?
What Will Happen When the Neutral is Broken in the Main Panel or Subpanel? The neutral wire provides a return path for current back to the power source, completing the…
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Why Must Neutral and Ground Wires Be Bonded in the Main Panel?
Why Do Neutral and Ground Conductors Need to Be Bonded in the Main Panel? According to NEC Article 250, both the neutral and ground wires must be connected only in…
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Why are Neutral and Ground Wires Separated in a Subpanel?
Why Do Neutral and Ground Conductors Need to Be Separated in a Subpanel? According to NEC Article 250, neutral and ground wires must remain separate in subpanels. Bonding (connecting) the…
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Why are Electrical Busbars Rectangular Instead of Circular?
Why is the Preferred Shape of Busbars Rectangular or Flat Rather than Circular or Round Shaped Cables? What is an Electrical Busbar? An electrical busbar is a metallic strip or…
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What Happens When You Touch an Electrical Busbar?
What Happens When a Person Comes into Contact with a Live Busbar? Busbars in main panels and distribution boards are often fed by high voltage and current, for example, 7.2kV…
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How Does the Grounding System Work in Aircraft & Submarines?
How is Grounding in AC/DC Systems Used for Protection in Aircraft, Ships, and Submarines? Aircraft, ships, and submarines represent significant investments and require advanced levels of electrical protection. These vehicles,…
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What Does Hanging Shoes from Overhead Power Lines Mean?
What are the Reasons Behind Shoes Strung Up on Power Lines? You may have seen colorful aerial marker balls on power lines, but what does it mean when shoes are…
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Why Do Doorbells Use Low Voltage of 12V-24V AC Instead of DC?
Why is 12V AC Preferred in Doorbells over DC Voltage? The choice of using 12V AC (alternating current) instead of DC (direct current) for doorbells circuits is driven by several…
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Why Does an Electric Tester Not Work in DC Circuits?
Why Does an Electric Tester Work Only in AC, but Not in DC Circuits? Electric testers, often referred to as voltage testers, phase testers, mains testers or test pens, are…
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