Generally the instantaneous current is represented by ________

Define instantaneous current.

What is the sum of the instantaneous current values over one complete ac cycle?

If the instantaneous current in a circuit is given by I = 20 cos (omega t + phi) A , the rms value of the current is

If the instantaneous current in a circuit is given by i=2cos (omegat-phi) ampere, the r.m.s. value of the current is