Substation Design MCQs (Part-4)

What is the main purpose of a substation in a power system?

A To generate electricity
B To step up or step down voltage levels
C To store electrical energy
D To reduce electrical losses

What is the primary function of a circuit breaker?

A To isolate a part of the system during maintenance
B To interrupt fault currents
C To control voltage levels
D To measure power flow

Which device in a substation is used to monitor voltage?

A Current transformer
B Potential transformer
C Circuit breaker
D Relay

What is the purpose of a grounding system in a substation?

A To prevent overcurrent
B To provide a safe path for fault currents to the ground
C To regulate frequency
D To step down voltage levels

What is the role of a power transformer in a substation?

A To change frequency
B To step up or step down voltage levels
C To regulate current flow
D To store electrical energy

Which substation component is used to protect equipment from lightning-induced surges?

A Circuit breaker
B Lightning arrester
C Isolator
D Relay

What is the purpose of a relay in a substation?

A To step up voltage
B To detect and isolate faults
C To increase current flow
D To monitor power factor

What is the typical voltage range for a distribution substation?

A 33 kV to 220 kV
B 11 kV to 33 kV
C 400 kV and above
D Below 11 kV

Which substation layout is commonly used for compact urban areas?

A Outdoor layout
B Indoor layout
C Hybrid layout
D Modular layout

What is the purpose of a busbar in a substation?

A To store electrical energy
B To collect and distribute power to outgoing feeders
C To control fault current
D To measure current flow

What does the term “switchgear” refer to in substations?

A Voltage regulating devices
B Protective devices like circuit breakers and isolators
C Transformers
D Metering equipment

Which test measures the insulation strength of substation equipment?

A Load test
B Dielectric test
C Relay test
D Power factor test

What is the purpose of shunt capacitors in substations?

A To step up voltage levels
B To provide reactive power and improve power factor
C To protect equipment from surges
D To disconnect faulty sections

What is the main advantage of gas-insulated substations (GIS)?

A Lower cost
B Compact size and suitability for harsh environments
C Easier maintenance
D Higher voltage regulation

What is the role of a load break switch?

A To interrupt fault currents
B To disconnect loads under normal operating conditions
C To measure system frequency
D To regulate reactive power

What does “fault current” refer to in substations?

A Normal operating current
B Excess current caused by a fault like a short circuit
C Current used for grounding
D Backup current during maintenance

What is the purpose of a control panel in a substation?

A To step down voltage levels
B To monitor and control equipment operation
C To regulate frequency
D To provide grounding

Which device is used for voltage control in substations?

A Tap changer
B Relay
C Isolator
D Lightning arrester

What is the purpose of a protective relay?

A To interrupt the main supply
B To detect abnormal conditions and signal circuit breakers
C To step up voltage levels
D To store electrical energy

What is the importance of insulation coordination in substations?

A To increase power factor
B To match insulation levels with expected voltage stresses
C To reduce transmission losses
D To improve grounding systems