Basic Electricity Oral Questions for GP RatingWhat is electricity?→ Electricity is the flow of electric charge (electrons) through a conductor, like a wire.What is voltage?→ Voltage is the electrical pressure that pushes current through a circuit. It is measured in volts (V).What is current?→ Current is the flow of electrons in a circuit. It is measured in amperes (A).What is resistance?→ Resistance is the opposition to the flow of current in a circuit. It is measured in ohms (Ω).What is the unit of power?→ The unit of electrical power is the watt (W).What is Ohm’s Law?→ Ohm’s Law: V = I × R, where:V = VoltageI = CurrentR = ResistanceWhat is the difference between AC and DC?→ AC (Alternating Current): Current changes direction periodically.→ DC (Direct Current): Current flows in one direction only.What is a fuse?→ A fuse is a safety device that breaks the circuit when current exceeds the safe limit to prevent damage or fire.What is a circuit breaker?→ A circuit breaker is an automatic switch that turns off the electrical circuit during overload or short circuit.What is the function of an earth wire?→ Earth wire provides a path for excess current to safely go into the ground and protects against electric shock.What is a short circuit?→ A short circuit happens when a live wire touches a neutral or ground wire, causing excess current flow and possible damage.Why is insulation important?→ Insulation prevents current from leaking and protects people from electric shock.Name any two types of electrical hazards.→ Electric shock, Fire due to short circuit.What is a generator?→ A generator converts mechanical energy into electrical energy.What precautions should you take while working with electricity onboard?→ Use dry hands, wear safety gear, ensure power is off before touching wires, and follow ship’s safety procedures.⚡ Additional Basic Electricity Oral Questions for GP Rating16. What is a conductor?→ A conductor is a material that allows electric current to pass through easily (e.g., copper, aluminum).17. What is an insulator?→ An insulator is a material that does not allow current to pass through (e.g., rubber, plastic, glass).18. What is the purpose of a switch?→ A switch is used to open or close an electrical circuit to control the flow of current.19. What is the function of a multimeter?→ A multimeter is used to measure voltage, current, and resistance in an electrical circuit.20. What is the standard voltage used onboard ships?→ Ships may use 110V, 220V, or 440V AC, depending on the system.21. What is a battery?→ A battery stores electrical energy in chemical form and provides DC power.22. What is polarity in electricity?→ Polarity refers to the positive (+) and negative (–) terminals in a DC circuit.23. What is an electric motor?→ A motor converts electrical energy into mechanical energy (used to run pumps, fans, etc.).24. What is grounding or earthing?→ Grounding means connecting the electrical system to the earth to prevent electric shock.25. What happens if you touch a live wire?→ You may receive an electric shock, which can be dangerous or fatal.26. Name any two personal protective equipment (PPE) used during electrical work.→ Insulated gloves, safety shoes.27. What is the color coding of electrical wires?→ Generally:· Red or Brown – Live wire· Black or Blue – Neutral wire· Green/Yellow – Earth wire(Color codes may vary by country/ship.)28. What should you do if someone gets an electric shock?→ Switch off the power, use a non-conductive stick to move the person, and call for medical help.29. What is an overload?→ Overload happens when too much current flows through a circuit, which can overheat wires and damage equipment.30. What is a capacitor?→ A capacitor stores electrical energy and is used in circuits for various functions like starting motors.31. What is an inverter?→ An inverter converts DC to AC power.32. What is a transformer?→ A transformer is used to increase (step-up) or decrease (step-down) voltage in AC circuits.33. Why is electrical equipment bonded to the hull on a ship?→ To prevent static electricity buildup and ensure safety during faults.34. Why is 440V dangerous?→ It is a high voltage and can cause severe electric shock or burns.35. What is a solenoid?→ A solenoid is a coil of wire that acts like a magnet when electricity flows through it.What is the function of a relay?→ A relay is an electrically operated switch used to control a high-power circuit with a low-power signal.What is a diode?→ A diode allows current to flow in only one direction.What is the function of a circuit diagram?→ A circuit diagram shows the components and wiring of an electrical circuit for easy understanding and maintenance.What is a terminal block?→ A terminal block is used to connect wires together safely in an electrical panel.Why is proper lighting important in the engine room?→ To ensure safe working conditions and avoid accidents or errors while working on machinery.What is a three-phase supply?→ A three-phase supply has three alternating currents, each 120° apart, providing more power efficiently.What is a single-phase supply?→ A single-phase supply has only one alternating current and is used for smaller loads.What is meant by ‘live’ wire?→ A live wire carries current from the power source to the equipment.What is a ‘neutral’ wire?→ A neutral wire completes the circuit by carrying current back to the power source.What is a megger?→ A megger (megohmmeter) is used to measure insulation resistance of electrical cables.What does LUX mean in lighting?→ Lux is the unit of light intensity. It measures the amount of light on a surface.Why are emergency lights provided on-board?→ To provide lighting during power failure or blackout for safe evacuation and emergency operations.What is a load?→ A load is any electrical device or equipment that consumes electrical power.What is a power factor?→ Power factor is the ratio between real power and apparent power. A high power factor means efficient power usage.What are the dangers of using a damaged extension cord?→ Risk of short circuit, electric shock, or fire hazard.Why are electrical panels kept locked onboard?→ To prevent unauthorized access and ensure safety.What is an ELCB or RCCB?→ ELCB (Earth Leakage Circuit Breaker) and RCCB (Residual Current Circuit Breaker) are safety devices that cut power during earth leakage.What is static electricity?→ Static electricity is the buildup of electrical charge on the surface of objects, which can cause sparks.What is bonding?→ Bonding is the electrical connection between metallic parts to equalize potential and avoid sparks.Why is regular electrical maintenance important on a ship?→ To ensure safety, avoid breakdowns, and comply with maritime regulations. 🔌 Basic Questions on Electric Resistance for GP Rating Oral Exam1. What is resistance?→ Resistance is the opposition to the flow of electric current in a circuit.2. What is the unit of resistance?→ The unit of resistance is Ohm (Ω).3. What instrument is used to measure resistance?→ Resistance is measured using an Ohmmeter or Multimeter.4. What is the symbol of resistance in a circuit diagram?→ The symbol is a zig-zag line (R).5. Which materials have high resistance?→ Insulators like rubber, plastic, and glass have high resistance.6. Which materials have low resistance?→ Conductors like copper, aluminum, and silver have low resistance.7. What is the effect of resistance on current?→ Higher resistance means less current flows.→ Lower resistance means more current flows.8. What is Ohm’s Law?→ V = I × R, where:o V = Voltageo I = Currento R = Resistance9. What happens if resistance increases in a circuit?→ Current decreases, and some energy may be lost as heat.10. Why are resistors used in electrical circuits?→ To control or limit the current flow and protect components.11. Does the length of a wire affect resistance?→ Yes. Longer wires have more resistance.12. Does the thickness of a wire affect resistance?→ Yes. Thicker wires have less resistance.13. What is the relationship between resistance and temperature?→ In most conductors, resistance increases with temperature.14. Why does a fuse wire have high resistance?→ So it heats up and melts quickly when excess current flows, breaking the circuit for safety.15. Give an example of where resistance is useful onboard.→ Electric heaters and toaster coils work based on resistance heating.