Self-study
Increasing the electrical load carried on a transmission line increases the line's temperature, and too great a load will cause the line to exceed its maximum operating temperature. ███ ██████ ███████████ ██ ████ ████████ ██ ████ █████ ███ ██████████ ██████ █████ ████ ███ ████ ████ ████ █████ ██████ ███ ████ ███████ ██████ █ ████ █████ ██ ████ ████ ████ ████ ███████ ████████ ██ ███
Summary
Increasing an electrical load on a transmission line causes the line’s temperature to increase. Too high of a load causes the line to exceed its maximum operating temperature. However, the temperature is also affected with wind speed and direction. Strong winds cool the line more than light winds. Winds blowing across the line provide more cooling than do winds blowing parallel to the line.
Strongly Supported Conclusions
When wind speed increases, the load a transmission line can carry without exceeding maximum operating temperature also increases.
At the same wind speed, perpendicular winds allow a transmission line to carry a greater load without exceeding maximum operating temperature compared to parallel winds.
17.
Which one of the following ██ ████ ████████ █████████ ██ ███ ███████████ ██████
a
Electrical utility companies █████████ ████████ ███ ██████████ ████ ██ █████ ████████████ █████ ██ ████ ██ █████ ███ ████ ███ █ ██████ ███████ ███████
This answer is unsupported. We don’t know how electrical utility companies usually operate. The stimulus only tells us about transmission line temperatures.
b
Transmission lines that ███ ████████ ██ ███ ██████████ █████ ███ █████████ █████ ███████ ██████████ █████ ████ █████████ █████████ █████ ██ █ █████ █████ ██ ███ ██████████ ██████
This answer is anti-supported. Based on the stimulus, the winds blowing at a right angle across the line would cool a line more than winds blowing parallel to the line.
c
The electrical load ████ █ ████████████ ████ ███ █████ ███████ ████████ ███ ███████ █████████ ███████████ █████████ ████ ███ ████ █████ ██████████
This answer is strongly supported. Load capacity is correlated with the temperature of a transmission line. The more the wind cools the line, the greater load capacity the line has.
d
Air temperature has ████ ██████ ██ ███ ███████████ ██ █ ████████████ ████ ████ ████ █████ █████
This answer is unsupported. We don’t know how much the surrounding air temperature could affect a transmission line’s temperature compared to the wind speed.
e
The maximum operating ███████████ ██ █ ████████████ ████ ██ ███████ ██ █████ ████ ████ ██ ████ █████
This answer is unsupported. Wind allows the line to carry a greater load without reaching its maximum temperature. Nothing in the stimulus indicates that the maximum temperature itself ever changes.