NEW
Font size
WorksheetsHeat transfers in a thermos flask
Total questions: 10
Worksheet time: 5mins
A vacuum flask is designed to reduce the rate of heat transfer. What method of heat transfer are reduced by the silvered surfaces?
Conduction
Convection
Radiation
Which surfaces are the best absorbers and emitters of radiation?
Light and shiny
Light and dull
Dark and shiny
Dark and dull
Which surfaces are the poorest absorbers and emitters of radiation?
Light and shiny
Light and dull
Dark and shiny
Dark and dull
A vacuum flask is designed to reduce the rate of heat transfer. What methods of heat transfer are reduced by the plastic cap?
Convection and radiation
Conduction and convection
Conduction and radiation
What material is the best conductor of heat?
Plastic
Paper
Metal
Glass
Inside the thermos flask is a silver bottle. What heat transfer will the silver bottle reduce?
Conduction
Convection
Radiation
Why does a vacuum reduce heat transfer by convection and conduction?
Because the vacuum sucks the heat away
Because the vacuum doesn't contain particles
Because the vacuum stops all transfers of heat
The diagram shows a gas flame patio heater. Why is the top surface of the reflecting hood a light, shiny surface rather than a dark, matt surface?
Because light shiny surfaces are poor emitters of radiation
Because customers prefer light shiny surfaces to dull black surfaces
Because dull, matt surfaces are poor emitters of radiation
The plastic cap or stopper is often made of plastic. How does this reduce heat transfer
It is a good insulator so reduces conduction
It is a good conduction so reduces convection
It is shiny so reduces radiation
Glass and plastic are both good thermal insulators. What could a disadvantage of using glass be?
Glass is transparent so you'd be able to see the liquid inside
The glass is brittle and can break if dropped
Glass would melt if hot water is added
