A single-phase $SCR$ based $ac$ regulator is feeding power to a load consisting of $5$ $Ω$ resistance and $16$ $mH$ inductance. The input supply is $230$ $V$, $50$ $Hz$ ac. The maximum firing angle at which the voltage across the device becomes zero all throughout and the rms value of current through $SCR$, under this operating condition, are
1. $30^0$ and $46$ $A$
2. $30^0$ and $23$ $A$
3. $45^0$ and $23$ $A$
4. $45^0$ and $32$ $A$