Hi friends..I am very confused with the magnetic behavior of a CT. CT secondary should never be left open.Okay I understand why. But how exactly does a shorted secondary cancel the primary flux? For that the primary and secondary currents must be 180 degrees out of phase while Lenz's law states it should be 90 degrees due to the di/dt of Ip. In power transformers,primary draws excess current on loading and 180 degree phase difference is established. But in CT,primary current is fixed. Also,if CT is somehow switched on at the zero-crossing instant of primary current, CT will tend to oppose the increase in flux but if it is switched on just after the peak of Ip, it will oppose the decrease in the flux and try to maintain the previous flux. This is baffling me. What does the secondary do exactly?? Does it oppose the primary flux or the change in primary flux?? What is the steady state waveform of secondary current?? What is its phase relationship with Ip?? Please help me with actual physics behind this..I am sick of the usual 'equivalent circuit' method and bunch of formulae..Please could anybody explain the actual physics?? I am eagerly waiting..