48. The average value of a triangular or sawtooth wave is __________ times its peak value.

The maximum peak-to-peak value of an AM wave is 45 V. The peak-to-peak value of the modulating signal is 20 V. What is the percentage of modulation? 

4.1 The current in an ac circuit at any time 𝑡 seconds is given by: 𝑖(𝑡) = 120 sin(100𝜋𝑡 +
0.36) amperes. Determine:
4.1.1 The peak value, the periodic time, the frequency and phase angle relative to
120 sin(100𝜋𝑡). 
4.1.2 The value of the current when 𝑡 = 0. 
4.1.3 The time when the current first reaches 60 A. 
4.1.4 The time when the current is first at maximum. 

A power station has a load cycle as under

260 MW for 6 hrs  200 MW for 8 hrs 160 MW for 4 hrs  100 MW for 6 hrs

If the power station is equipped with 4 sets of 75 MW each, calculate the daily fuel requirement if the calorific value of the oil used were 10,000 Kcal/kg and the average heat rate of the station were 2,860 Kcal/kW.

a. 1890 tons

b. 3452 tons

c. 7641 tons

d. 1258.4 tons