A transformer substation's bus has 4 outward lines A, B, C, and D, all with wave impedance of 400 . At time t=0 s, an infinitely long rectangular wave of magnitude 1000 kV arrives at the bus from Line A. This can be viewed as if there is a 1000 kV voltage source connected at the other end (not the bus) of Line A.

(a) Calculate the magnitude of the refraction wave on Line C and the magnitude of the reflection wave on Line A.

(b) Assume the wave propagation speed along all four lines is 3108 m/s. Sketch the snapshot of the wave process at t=510-6 s.

(c) Further, assume the length of Line A is 3000 m, and the internal impedance of the 1000 kV voltage source is 100 . Quantitatively describe what will happen on Line A between t=510-6 s and t=1510-6 s.