The main reason for making the cover of a vacuum flask airtight is to prevent heat loss by? By: Sunday|Published on: Nov 16|Categories: Physics JAMB| 0 comments A. convection B. conduction C. radiation D. evaporation Correct Answer: Option A – convection Users Also Read These:Fidelity guarantee insurance is a cover against loss…Fidelity guarantee is an insurance cover against…In a good thermos flask; the main cause of heat loss is?The inside of a vacuum flak is usually coated with…Tea pots are often silver-coated to prevent heat loss by?SEE ALSO The equivalent capacitance of a 3μF capacitor and a 6μF capacitor connected in parallel is?