The relative humidity in an incubator is usually set at? by Sunday | Dec 20 | Agricultural Science WAEC | 0 comments A. 10% – 30% B. 40% – 60% C. 70% – 80% D. 90% – 100%. Correct Answer: Option B = 40% – 60% Users Also Read These:The instrument used for measuring relative humidity…The mass of water vapour in a given volume of air is…The instrument used to measure the relative humidity is?When there is a large difference in the reading of…The mass of water vapour in a given volume of air is…