Transmission and Distribution Systems MCQs (Part-13)

What is the primary purpose of transmission lines in a power system?

A To generate electricity
B To transmit power over long distances
C To store energy for future use
D To convert AC to DC

Which type of system is responsible for delivering power to end users?

A Transmission system
B Distribution system
C Substation system
D Generation system

Why are step-up transformers used in power systems?

A To increase current flow
B To increase voltage levels for efficient transmission
C To reduce transmission losses
D To stabilize frequency

What is the primary disadvantage of underground cables compared to overhead lines?

A Higher current carrying capacity
B Higher initial installation cost
C More exposure to environmental factors
D Lower insulation requirements

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

A To store energy
B To regulate voltage and control power flow
C To generate electricity
D To increase conductor size

What happens when the voltage in a transmission line exceeds the breakdown strength of air?

A Ferranti effect
B Corona discharge
C Dielectric breakdown
D Eddy current loss

What is the primary advantage of aluminum over copper as a conductor?

A Higher resistance
B Lower weight and cost
C Better conductivity
D Easier to install

What is the primary role of a suspension insulator in overhead transmission lines?

A To reduce line impedance
B To support the conductor and provide insulation
C To store energy
D To increase current carrying capacity

What is the typical voltage range for high-voltage transmission lines?

A 11–33 kV
B 110–765 kV
C 33–110 kV
D 0–1 kV

What is the purpose of reactive power management in a power system?

A To reduce system frequency
B To regulate voltage levels and improve power factor
C To store energy
D To increase transmission line losses

What is the unit of apparent power in an AC system?

A Watt
B VA (Volt-Ampere)
C VAR (Volt-Ampere Reactive)
D Ohm

What is the primary function of grounding in a power system?

A To increase voltage levels
B To dissipate fault currents safely into the ground
C To reduce inductance
D To stabilize frequency

What is the Ferranti effect in transmission lines?

A Voltage drop at the receiving end
B Voltage rise at the receiving end under light load conditions
C Increase in line resistance
D Reduction in capacitance

What is the primary cause of sag in transmission lines?

A High resistance
B Conductor weight and temperature changes
C Excessive current flow
D Poor insulation

What is the main advantage of aluminum over copper as a conductor?

A Higher resistance
B Lower weight and cost
C Better conductivity
D Easier to install

What is the function of a lightning arrester in a power system?

A To step up voltage levels
B To protect the system from overvoltage caused by lightning strikes
C To regulate power factor
D To reduce current flow

What is the purpose of a smart meter in a distribution system?

A To step up voltage
B To measure energy usage and provide real-time data
C To balance load demand
D To reduce capacitance

What is the primary advantage of microgrids?

A They reduce power factor
B They provide localized and reliable power supply
C They increase transmission losses
D They eliminate voltage fluctuations

What is the primary cause of sag in transmission lines?

A High resistance
B Conductor weight and temperature changes
C Excessive current flow
D Poor insulation

What is the main advantage of aluminum over copper as a conductor?

A Higher resistance
B Lower weight and cost
C Better conductivity
D Easier to install