12 midnight 4 a.m. 9 a.m. 4. The load curve of an electrical system is linear with the following values at different times of the day: Time 12 noon 5 p.m. 8 p.m. 12 midnight Load (MW) 40 40 100 100 120 150 40 Plot the following curves: (a) Chronological load curve (b) Load-duration curve (c) Load-energy curve Calculate the energy required by the system in one day and the system daily load factor.