NextMockಪರೀಕ್ಷೆಗಳನ್ನು ಹುಡುಕಿ, ಉದಾ. SSC CGL, UPPSC, Lekhpal
State PCS PYQPrelims 2019

UPPCS · ಪ್ರಶ್ನೆ 50

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

  1. Conduction
  2. Convection and radiation
  3. Both (a) and (b)
  4. None of the above
ಉತ್ತರ ತೋರಿಸು ಮತ್ತು ವಿವರಣೆ

ಉತ್ತರ: (C) Both (a) and (b)

ವಿವರಣೆ

A vacuum flask's double wall with a vacuum stops conduction and convection, and the silvered surfaces cut radiation. So heat is not gained or lost by either (a) or (b).