A single-phase circuit is composed of two parallel conductors, each of radius 4 mm, spaced 1.2 m apart in air. The p.d between the conductors at a frequency of 50 Hz is 15 kv. Determine, for a 1 km length of line, (a) the capacitance of the conductors, (b) the value of charge carried by each conductor and (c) the charging current.