Transmission and Distribution Systems MCQs (Part-4)

What is the main advantage of overhead lines compared to underground cables?

A Lower installation cost
B Easier to maintain
C Higher power capacity
D Reduced sag

Which type of transmission line is typically used for interconnecting power grids?

A Medium voltage lines
B Low voltage lines
C High voltage lines
D Superconducting lines

What is the primary purpose of a conductor in a transmission line?

A To support insulators
B To transmit electric power
C To maintain mechanical tension
D To provide insulation

Which type of insulator is most commonly used in high-voltage overhead transmission lines?

A Pin insulator
B Suspension insulator
C Shackle insulator
D Stay insulator

What is the purpose of maintaining proper sag in overhead lines?

A To reduce conductor resistance
B To prevent snapping during temperature changes
C To reduce corona losses
D To increase the current-carrying capacity

What is the term used for the loss of electrical power due to resistance in the transmission line?

A Corona loss
B Dielectric loss
C Copper loss
D Eddy current loss

Why are high-voltage lines preferred for long-distance power transmission?

A To reduce the size of the conductors
B To reduce current and minimize losses
C To eliminate the need for transformers
D To improve insulation

What is the function of a stay wire in overhead lines?

A To support the conductor mechanically
B To carry the current
C To insulate the line
D To increase line voltage

Which material is commonly used as an insulator for overhead transmission lines?

A Aluminum
B Steel
C Porcelain
D Copper

What is the effect of using conductors with larger diameters in transmission lines?

A Increases resistance
B Reduces corona loss
C Decreases current flow
D Increases inductance

What is the main purpose of cross-arms in overhead lines?

A To insulate the line
B To support conductors
C To carry current
D To reduce sag

What is the common spacing between phases in high-voltage transmission lines determined by?

A Voltage level
B Current level
C Line length
D Cross-arm spacing

What is the main disadvantage of overhead transmission lines?

A High installation cost
B Vulnerability to weather conditions
C Limited current carrying capacity
D High corona loss

Which factor primarily affects the selection of conductor material in transmission lines?

A Cost and conductivity
B Weight and color
C Tensile strength only
D Environmental resistance only

What is the main cause of power loss in underground cables?

A Dielectric loss
B Corona loss
C Copper loss
D Eddy current loss

Which type of conductor arrangement is used to minimize skin effect?

A Solid conductor
B Stranded conductor
C Twisted pair conductor
D Bundled conductor

What is the purpose of a distribution board in a power system?

A To transmit high voltage
B To divide electrical power into multiple circuits
C To generate electrical power
D To store energy

What is the primary reason for using transmission towers instead of wooden poles for high-voltage lines?

A Higher current carrying capacity
B Greater mechanical strength
C Better insulation
D Lower installation cost

What is the primary factor that determines the voltage drop in a transmission line?

A Conductor material
B Conductor length and resistance
C Insulator material
D Cross-arm spacing

What is the purpose of earthing in a transmission system?

A To provide insulation
B To ensure safety and fault current dissipation
C To stabilize voltage levels
D To reduce resistance