1. What is the primary dielectric medium used in Vacuum Circuit Breakers (VCBs)?
(a). Gas
(b). Oil
(c). Air
(d). High vacuum
2. How is the vacuum level measured in Vacuum Circuit Breakers (VCBs)?
(a). PSI
(b). Volts
(c). Torr
(d). Amperes
3. What is the term used for the arc formed when the contacts of a VCB are separated in vacuum?
(a). Thermal arc
(b). Cold cathode arc
(c). Electric arc
(d). Ionized arc
4. How is the vacuum arc in VCBs different from conventional arcs?
(a). Involves only neutral atoms
(b). Involves only ions
(c). Involves only electrons
(d). Involves all of the above
5. What is released from the contacts to create a plasma for extinguishing the arc in VCBs?
(a). Gas
(b). Oil
(c). Metal vapor
(d). Air
6. What advantage does VCBs have in terms of dielectric strength recovery after arc extinction?
(a). Slow recovery
(b). Moderate recovery
(c). Rapid recovery
(d). No recovery
7. What property of contact material influences the cutting of current in VCBs?
(a). Resistivity
(b). Thermal conductivity
(c). Density
(d). Hardness
8. Why do Vacuum Circuit Breakers not require filling with oil or gas?
(a). Self-containment
(b). Environmental regulations
(c). Cost-effectiveness
(d). Technological advancement
9. What makes VCBs suitable for capacitor and cable switching?
(a). Slow recovery
(b). Environmental friendliness
(c). Rapid recovery of dielectric strength
(d). Compact design
10. What is a notable environmental advantage of VCBs?
(a). Emission of gases
(b). Non-explosive performance
(c). High maintenance requirements
(d). Slow switching speed
11. What is a limitation in the production of vacuum interrupters, contributing to their high cost?
(a). Low technology requirements
(b). Lack of skilled labor
(c). Advanced technology production
(d). Minimal equipment needed
12. What is the rated voltage limitation for a single interrupter in VCBs?
(a). 10 kV
(b). 15 kV
(c). 20 kV
(d). 25 kV
13. What happens if vacuum is lost in a Vacuum Circuit Breaker?
(a). Repairable on-site
(b). Requires minimal maintenance
(c). Becomes useless and not repairable on-site
(d). Causes an explosion
14. In which industrial setting are VCBs used for high-speed switching?
(a). Residential
(b). Agricultural
(c). Industrial
(d). Commercial
15. What are VCBs ideal for in terms of specialized switching?
(a). Residential switching
(b). Transformer switching
(c). Commercial switching
(d). Agricultural switching
16. In what scenarios are VCBs considered a cost-effective solution?
(a). High fault interference
(b). Low fault interference
(c). Moderate fault interference
(d). No fault interference
17. Why are VCBs considered maintenance-friendly?
(a). Require frequent maintenance
(b). Minimal maintenance requirements
(c). No maintenance required
(d). On-site repairable
18. What is the main technological advantage of Vacuum Circuit Breakers in electrical switching?
(a). Slow switching speed
(b). Rapid recovery
(c). Environmental friendliness
(d). Versatility
19. What role do Vacuum Circuit Breakers play in electrical power systems?
(a). Secondary
(b). Non-essential
(c). Primary
(d). Auxiliary
20. How do VCBs utilize the properties of high vacuum in their design?
(a). For heating
(b). For cooling
(c). For efficient interruption of electrical currents
(d). For generating electricity
21. What contributes to the compactness of Vacuum Circuit Breakers?
(a). Large size
(b). Use of gases
(c). Use of oils
(d). Self-contained design
22. What makes VCBs suitable for a variety of voltage and application scenarios?
(a). Limited applications
(b). Compact design
(c). Environmental limitations
(d). Voltage limitations
23. What type of arc is formed during the interruption of the contacts in a Vacuum Circuit Breaker?
(a). Thermal arc
(b). Cold cathode arc
(c). Electric arc
(d). Ionized arc
24. What is the primary advantage of the quick recovery of dielectric strength in VCBs?
(a). Slow fault resolution
(b). Fast fault resolution
(c). No fault resolution
(d). Costly fault resolution
25. In which situations are Vacuum Circuit Breakers highly suitable for widespread use?
(a). Urban areas
(b). Rural areas
(c). Industrial areas
(d). Commercial areas
26. What distinguishes the vacuum arc in VCBs from conventional arcs?
(a). Involvement of gases
(b). Involvement of oils
(c). Involvement of electrons
(d). Involvement of neutral atoms, ions, and electrons
27. Why are VCBs considered environmentally friendly?
(a). Emission of gases
(b). Non-explosive performance
(c). High maintenance requirements
(d). Slow switching speed
28. What factor affects the cutting of current in Vacuum Circuit Breakers?
(a). Voltage
(b). Vapor pressure
(c). Electron emission properties
(d). Thermal conductivity
29. What role does metal vapor play in the interruption of the arc in VCBs?
(a). Creates the arc
(b). Extends the arc
(c). Extinguishes the arc
(d). Sustains the arc
30. What is the primary reason for using high vacuum as a dielectric medium in VCBs?
(a). Cost-effectiveness
(b). Advanced technology
(c). Efficient interruption of electrical currents
(d). Environmental regulations