What is the main function of a circuit breaker in a power system?
A Voltage regulation
B Fault isolation
C Frequency control
D Power generation
A circuit breaker is a protective device that isolates faulty sections of the system during a fault, such as a short circuit, preventing further damage to equipment and maintaining the stability of the power system.
What does a substation primarily do in a power system?
A Voltage regulation
B Fault detection
C Power generation
D Power distribution
Substations adjust the voltage levels in a power system. They step up voltage for transmission over long distances and step down voltage for safe distribution to consumers. They also provide important protective functions to ensure system safety.
What is the role of a protection relay in a power system?
A Power generation
B Voltage control
C Fault detection
D Power distribution
Protection relays are designed to monitor electrical circuits and detect faults such as short circuits or overloads. They automatically trigger circuit breakers to isolate faulty sections, preventing damage to the system and ensuring safe operation.
What is the function of a switchgear in a power system?
A Voltage transformation
B Fault isolation
C Power generation
D Load forecasting
Switchgear includes switches, circuit breakers, and fuses, which are used to protect electrical circuits. They detect faults, isolate affected parts of the system, and enable safe maintenance, helping to maintain the reliability of the power grid.
Which of the following components helps protect against electrical faults in a substation?
A Generator
B Circuit breaker
C Capacitor
D Transformer
Circuit breakers are installed in substations to protect electrical circuits from overloads or faults. They automatically disconnect parts of the system when a fault is detected, preventing further damage and ensuring the safety of the infrastructure.
What does a protective relay do when it detects a fault?
A Disconnects faulty circuit
B Stores energy
C Sends alarms
D Increases power flow
When a fault is detected, the protective relay triggers the circuit breaker to disconnect the affected part of the circuit. This isolates the fault, ensuring the rest of the system continues to operate without interference.
What is the primary purpose of grounding in a power system?
A Power factor correction
B Power generation
C Fault protection
D Voltage regulation
Grounding provides a safe path for fault currents to flow into the earth, preventing electrical shock hazards and reducing the risk of fire or equipment damage during faults. It is a critical part of electrical safety in power systems.
What type of fault occurs when a phase conductor comes into direct contact with the ground?
A Open circuit
B Ground fault
C Line-to-line fault
D Short circuit
A ground fault occurs when a phase conductor comes into direct contact with the earth or a grounded object, leading to a current flow into the ground. This type of fault is dangerous and requires quick isolation to prevent system damage.
What is the function of an isolator in a power system?
A Load balancing
B Voltage regulation
C Fault isolation
D Switching circuits
An isolator is used to isolate parts of a system for maintenance or during faults. It ensures that no current flows through the isolated section while maintenance work is being done, ensuring safety and preventing system disruptions.
What does the term “system redundancy” refer to in power systems?
A Energy storage
B Extra power generation capacity
C Backup components for reliability
D Backup protection devices
System redundancy involves adding backup components, such as extra circuit breakers or power lines, to ensure that the power system remains operational if one component fails. It enhances the reliability and availability of the grid.
Which of the following devices is used to detect and isolate faults in power transformers?
A Voltage regulator
B Protective relay
C Circuit breaker
D Capacitor bank
Protective relays are specifically designed to detect faults, such as short circuits or overloads, in transformers. They send signals to circuit breakers to isolate the faulty section, preventing further damage and ensuring the safety of the system.
What is the function of a busbar in a substation?
A Energy storage
B Voltage step up
C Power generation
D Power distribution
Busbars are used in substations to collect and distribute electricity from multiple incoming and outgoing lines. They act as a central point for distributing electrical power to various parts of the system, facilitating efficient operation.
What does a voltage regulator maintain in a power system?
A Voltage levels
B Power factor
C Frequency
D Current
A voltage regulator automatically adjusts the voltage level in the power system to ensure that it remains within a specified range. It maintains stable voltage for reliable operation of electrical equipment and prevents damage from over voltage or under voltage.
What is the primary function of a lightning arrester in a power system?
A Power generation
B Surge protection
C Voltage regulation
D Fault isolation
A lightning arrester protects electrical equipment from damage due to lightning strikes or voltage surges. It diverts the excess energy from a surge or lightning strike safely to the ground, preventing damage to critical system components.
Which of the following is used to protect power lines from lightning strikes?
A Capacitor bank
B Circuit breaker
C Transformer
D Lightning arrester
Lightning arresters are installed on power lines to protect them from the destructive effects of lightning strikes. They provide a path for the lightning energy to be safely conducted to the ground, preventing damage to the system.