• question_answer If the specific heats of dry air and water vapour are $1.00\,\,\text{kJ/kg}-K$ and $1.88\,\,\text{kJ/kg}-K$ respectively and the humidity ratio is 0.011, then the specific heat of moist air at  $25{}^\circ C.$ and 50% relative humidity will be A) $1.0207\,\,\text{kJ/kg}-K$          B) $1.869\,\,\text{kJ/kg}-K$C) $1.891\,\,\text{kJ/kg}-K$D) $0.9793\,\,\text{kJ/kg}-K$

${{c}_{p}}$ of moist air $=\,\,{{c}_{p}}$ of dry air + humidity Ratio $\times \,\,{{c}_{p}}$ of water vapour $=1.00+0.011\times 1.88$ $=1.0207\,\,\text{kJ/kg}\text{.}\,\text{K}$