A short-circuit test is conducted on a single-phase transformer by shorting its secondary. The frequency of input voltage is $1 ~ \mathrm{kHz}$. The corresponding wattmeter reading, primary current and primary voltage are $8 \mathrm{~W}, 2 \mathrm{~A}$ and $6 \mathrm{~V}$ respectively. Assume that the no-load losses and the no-load currents are negligible, and the core has linear magnetic characteristics. Keeping the secondary shorted, the primary is connected to a $2 \mathrm{~V}$ (RMS), $1 ~ \mathrm{kHz}$ sinusoidal source in series with a $\frac{1}{2 \pi \sqrt{5}} ~\mathrm{mF}$ capacitor. The primary current (RMS) will be_______________$\text{A}$ (rounded off to two decimal places).