$4($b$)$ Air at $35C$ DBT and $22C$ WBT is passed through a cooling coil. The apparatus

$[5]4$

dew point of the cooling coit is $4C.$ The heat extracted by the cooling coil from air is $12$ kW and the air flow rate is $45\frac{m^3}{m}in.$ Determine using psychrometry charts:

i$.$ Relative humidity of the air passing through the coil,

ii$.$ DBT$,$ WBT and relative humidity of the air leaving the coil, Coil by$-$pass factor.