(a) In a 3-phase, 4-wire system, the currents are in the A, B, and C lines under abnormal conditions of loading were as follows: IA = 100/30° A, 1b = 50/300° A, and Ic = 30/180° A

(i) Calculate the positive, negative, and zero-phase sequence currents in the A-line.
(ii) Calculate the return current in the neutral conductor.

(b) Check by sketching IA, IB, and Ic as the sum of the appropriate symmetrical components.

Plot schematically the tensile stress versus strain curves for a typical thermoplastic material at a temperature below its glass transition temperature (tg and at a temperature above its tg, respectively. do the same for a typical thermosetting material. list in a table any differences or similarities between the two materials at t> tg and t < tg, respectively, and relate them to the structures of the two types of polymers