WorksheetsQuiz on Fuses and Circuit Breakers
Total questions: 21
Worksheet time: 11mins
What is the primary function of a fuse?
To store electrical energy
To increase current flow
To protect against overloads and short circuits
To amplify voltage
Which type of fuse is designed to be reusable?
HRC fuse
Semi-enclosed fuse
Rewirable fuse
Cartridge fuse
What does the rated current of a fuse indicate?
The maximum voltage it can handle
The current it can carry indefinitely without fusing
The minimum current required to blow the fuse
The time it takes to blow under overload
What is the purpose of a circuit breaker?
To convert AC to DC
To store energy for later use
To isolate faulty parts of the power system
To increase the voltage in a circuit
What is the arcing time in a circuit breaker?
Time from opening of contacts to final arc extinction
Time from fault inception to trip signal
Time taken to detect a fault
Time taken to close the contacts
Which type of circuit breaker uses SF6 as an insulating medium?
Oil circuit breaker
SF6 circuit breaker
Vacuum circuit breaker
Air-blast circuit breaker
What is the minimum fusing current?
The maximum current rating of the fuse
The current required to reset the fuse
The current it can carry indefinitely
The current that causes the fuse to melt
What is the main advantage of HRC fuses?
They require frequent maintenance
They are the cheapest option
They can clear high fault currents quickly
They are reusable
What is the typical relaying time for electromechanical relays?
Less than one cycle
One cycle to five cycles
More than ten cycles
Five to ten cycles
Which type of relay is faster than electromechanical relays?
Digital relays
Static relays
Numerical relays
Mechanical relays
What is the arcing time generally between?
Three and four cycles
Two and three cycles
One and two half-cycles
One and four cycles
Which method of arc interruption is applicable only in case of AC circuit breakers?
Voltage Drop Interruption
Current Zero Interruption
Magnetic Field Interruption
High Resistance Interruption
What is the main disadvantage of using oil in oil circuit breakers?
It is non-flammable
It is inflammable and may pose a fire hazard
It has good cooling properties
It has high dielectric strength
What is the primary function of a resistance connected across the contacts of a circuit breaker?
To improve mechanical stability
To enhance dielectric strength
To reduce restriking voltage
To increase the arcing time
What is the main advantage of SF6 circuit breakers?
High noise levels during operation
Increased risk of fire hazards
High maintenance requirements
Compact design and less maintenance
What is the primary purpose of a circuit breaker in an electrical system?
To convert AC to DC
To protect electrical circuits from overloads and faults
To increase the voltage in a circuit
To store energy for later use
What is the typical response time for a modern digital relay?
Less than one cycle
One cycle to three cycles
More than five cycles
Three cycles to five cycles
Which type of fuse is specifically designed to handle high fault currents?
Rewirable fuse
HRC fuse
Cartridge fuse
Glass fuse
What is the primary advantage of using numerical relays over traditional relays?
They are less expensive
They provide more accurate measurements
They require more maintenance
They are larger in size
What is the typical lifespan of an HRC fuse under normal operating conditions?
5-10 years
1-2 years
20-30 years
Indefinite
Which type of circuit breaker is known for its ability to interrupt high fault currents without external energy?
Earth leakage circuit breaker
Air circuit breaker
Miniature circuit breaker
Hydraulic magnetic circuit breaker
