Q1: Which heat transfer methods will the vacuum layer of the thermal flask help to minimize?
Q2: Why is the inside of a thermos flask painted silver?
Q3: How does a thermos flask prevent the loss of heat?
Answers
Answer:
In order to estimate the frictional head loss in a pipe 1 m in diameter, through
which castor oil of specific gravity 0.96 and dynamic viscosity 9.9 poise, is to
be transported at the rate of 5000 litres per second, a test was conducted on
a pipe of diameter 50 mm using water at 15°C as the model fluid. Calculate
the discharge required for the model pipe.
Explanation:
01 - The vacuum prevents the heat loss by conduction because vacuum is a bad conductor of heat. The stopper prevents the heat loss convection because it is tightly sealed. And the inner reflecting layer prevents the heat loss by radiation.
2- The vacuum prevents the heat loss by conduction because vacuum is a bad conductor of heat. The stopper prevents the heat loss by convection because it is tightly sealed. And the inner reflecting layer prevents the heat loss by radiation.
3- The vacuum between the glass walls prevents heat loss by preventing radiation. Hint: A vacuum flask or thermos flask is designed so that it will not allow heat loss by any means of conduction or radiation. The vacuum prevents the heat loss by conduction because vacuum is a bad conductor of heat.