Specific heat capacity of dry air and water vapour are 1.005 and $1.88 \mathrm{~kJ} \mathrm{~kg}^{-1} \mathrm{~K}^{-1},$ respectively. In an energy conserving system, $1 \mathrm{~kg} \mathrm{~s}^{-1}$ air at $30{ }^{\circ} \mathrm{C}$ with constant absolute humidity of $0.02 \mathrm{~kg}$ water $(\mathrm{kg}$ dry air) $^{-1}$ is heated up to $65^{\circ} \mathrm{C}$. Water at the wet bulb temperature of air is then sprayed into the air so that the final temperature of the air-water vapour mixture is $40^{\circ} \mathrm{C}$. Latent heat of vapourization of water at $70{ }^{\circ} \mathrm{C}$ and $40{ }^{\circ} \mathrm{C}$ are 2334 and $2407 \mathrm{~kJ} \mathrm{~kg}^{-1}$, respectively.The absolute humidity of the exhaust air from the spray chamber in $\mathrm{kg}$ water $(\mathrm{kg} \text { dry air })^{-1}$ is
(A) 0.027
(B) 0.029
(C) 0.031
(D) 0.033
Specific heat capacity of dry air and water vapour are 1.005 and $1.88 \mathrm{~kJ} \mathrm{~kg}^{-1} \mathrm{~K}^{-1},$ respectively. In an energy conserving system, $1 \mathrm{~kg} \mathrm{~s}^{-1}$ air at $30{ }^{\circ} \mathrm{C}$ with constant absolute humidity of $0.02 \mathrm{~kg}$ water $(\mathrm{kg}$ dry air) $^{-1}$ is heated up to $65^{\circ} \mathrm{C}$. Water at the wet bulb temperature of air is then sprayed into the air so that the final temperature of the air-water vapour mixture is $40^{\circ} \mathrm{C}$. Latent heat of vapourization of water at $70{ }^{\circ} \mathrm{C}$ and $40{ }^{\circ} \mathrm{C}$ are 2334 and $2407 \mathrm{~kJ} \mathrm{~kg}^{-1}$, respectively.The absolute humidity of the exhaust air from the spray chamber in $\mathrm{kg}$ water $(\mathrm{kg} \text { dry air })^{-1}$ is
(A) 0.027
(B) 0.029
(C) 0.031
(D) 0.033