WorksheetsApprentices Assessment Day 2
Total questions: 15
Worksheet time: 8mins
What is the primary advantage of using aluminium conductors in overhead lines?
Higher tensile strength than copper
Lower cost and weight
Better conductivity than copper
Easier to install
Which of the following is a common type of overhead line construction?
Single pole
Double circuit
Underground
Composite
What is the purpose of using insulators in overhead power lines?
To increase current flow
To prevent short circuits
To support conductors and prevent leakage to ground
To reduce line losses
What is a busbar primarily used for in electrical systems?
To connect transformers to the grid
To distribute power to multiple circuits
To store electrical energy
To convert AC to DC
Which material is commonly used for busbars due to its excellent conductivity?
Steel
Copper
Aluminum
Brass
What is the main disadvantage of using a busbar system?
High installation cost
Limited load capacity
Requires frequent maintenance
Larger physical footprint compared to cables
Which method is commonly used for installing underground conductors?
Direct burial
Overhead suspension
Cable trays
Surface mounting
What is the purpose of using cable trays in conductor installation?
To increase insulation resistance
To provide mechanical support and organization for cables
To improve thermal conductivity
To reduce electromagnetic interference
When installing conductors, what factor must be considered to prevent overheating?
Length of the conductor only
Ambient temperature and load current
Type of insulation only
Colour of the conductor
What are line losses primarily caused by in electrical transmission systems?
Voltage drops across transformers
Resistance of conductors
Poor insulation
Load imbalances
What is the typical height for overhead transmission lines above ground level?
3-5 meters
5-10 meters
10-15 meters
15-20 meters
Which type of loss occurs due to the heating effect in conductors?
Dielectric loss
Inductive loss
Resistive (I²R) loss
Capacitive loss
What is typically done to minimize line losses in high-voltage transmission lines?
Increase resistance
Use thicker conductors
Decrease voltage levels
Shorten transmission distance
How can transmission efficiency be improved?
By increasing the resistance of conductors
By using higher voltage levels for transmission
By reducing conductor diameter
By increasing load current
What is the maximum allowable voltage drop for most electrical installations according to standard practices?
Correct Answer: B
Marks: 1
A) 1%
B) 3%
C) 15%
D) 10%
