UPPCS 2019 Pre

A liquid remains hot or cold for a long time in thermus flask because there is no loss or gain of heat by

Verified Answer
A. Conduction
B. Convection and radiation
C. Both (a) and (b)
D. None of the above

Explanation:

A thermos flask is designed to minimize heat transfer through all three mechanisms: conduction (vacuum, stopper), convection (vacuum), and radiation (silvered surfaces). Therefore, both conduction and convection/radiation are minimized.