A 100 $\Omega$ resistance and a capacitor of 100 $\Omega$ reactance are connected in series across a 220 V source. When the capacitor is 50% charged, the peak value of the displacement current is:

$(i_d)_{max} = (i_c)_{max} = i_0 = \frac{\varepsilon_0}{Z} = \frac{220\sqrt{2}}{\sqrt{100^2 + 100^2}}$
$(i_d)_{max} = \frac{220\sqrt{2}}{100\sqrt{2}} = 2.2$ A
As the amplitude of displacement current is asked, the charge on the capacitor does not matter.