Question: What is the relative humidity of air at 30° C Dry Bulb and 10 C Dew Point? A. 15% B 29% C 39% D None of the

Question: What is the relative humidity of air at 30° C Dry Bulb and 10 C Dew Point? 

A. 15% 

B 29% 

C 39% 

D None of the

Answer:- 

GIVEN,  

                Dry bulb temprature , Tdb = 30 degree celcius

                Dew point temprature , Tdp = 10 degree celcius

Now,  By using Psychrometric chart 

Specific enthalpy , h = 49.65 KJ/Kg

Humidity ratio , w = 0.0076 Kg/Kg

Relative humidity, RH = 29 %

Wet bulb temprature , Twb = 17.6 degree celcius

So, option "B" is correct