Advertisements
Advertisements
Question
Is the bulb of a thermometer made of diathermic or adiabatic wall?
Advertisements
Solution
As diathermic walls allow the exchange of heat energy between two systems and adiabatic walls do not, hence. diathermic walls are used to make the bulb of a thermometer.
APPEARS IN
RELATED QUESTIONS
On a cold winter night you are asked to sit on a chair. Would you like to choose a metal chair or a wooden chair? Both are kept in the same lawn and are at the same temperature.
An ordinary electric fan does not cool the air, still it gives comfort in summer. Explain
The temperature of the atmosphere at a high altitude is around 500°C. Yet an animal there would freeze to death and not boil. Explain.
Newton's law of cooling is a special case of
Answer the following question.
State Newton’s law of cooling and explain how it can be experimentally verified.
A tub of hot water cools from 80°C to 75°C in time t1 from 75°C to 70°C in time t2, and from 70°C to 65°C in time t3 then:
Two circular discs A and B with equal radii are blackened. They are heated to the same temperature and are cooled under identical conditions. What inference do you draw from their cooling curves?
A cup of coffee cools from 90°C to 80°C in t minutes, when the room temperature is 20°C. The time taken by a similar cup of coffee to cool from 80°C to 60°C at a room temperature same at 20°C is ______.
A glass full of hot milk is poured on the table. It begins to cool gradually. Which of the following is correct?
- The rate of cooling is constant till milk attains the temperature of the surrounding.
- The temperature of milk falls off exponentially with time.
- While cooling, there is a flow of heat from milk to the surrounding as well as from surrounding to the milk but the net flow of heat is from milk to the surounding and that is why it cools.
- All three phenomenon, conduction, convection and radiation are responsible for the loss of heat from milk to the surroundings.
One day in the morning, Ramesh filled up 1/3 bucket of hot water from geyser, to take bath. Remaining 2/3 was to be filled by cold water (at room temperature) to bring mixture to a comfortable temperature. Suddenly Ramesh had to attend to something which would take some times, say 5-10 minutes before he could take bath. Now he had two options: (i) fill the remaining bucket completely by cold water and then attend to the work, (ii) first attend to the work and fill the remaining bucket just before taking bath. Which option do you think would have kept water warmer? Explain.
In 5 minutes, a body cools from 75°C to 65°C at a room temperature of 25°C. The temperature of the body at the end of the next 5 minutes is ______°C.
According to Newton's law of cooling, how does the rate of cooling depend on temperature?
In \[\frac{dT}{dt}\] = C(T−T₀), what does the constant C represent?
If we plot \[\frac{dT}{dt}\] vs (T−T₀), what graph do we get?
Why must the surrounding temperature T₀ remain constant in the experiment?
A body cools from temperature \[(3\theta)^{\circ}C\] to \[(2\theta)^{\circ}C\] in 10 minute. Then it cools from \[(2\theta)^{\circ}C\] to \[(\theta_1)^{\circ}C\] in next 10 minutes. The room temperature is \[(\theta)^{\circ}C.\] Assuming that the newton's law of cooling is applicable the value of \[(\theta_1)^{\circ}C\] is ______.
Why is the calorimeter kept in open air or a constant-temperature enclosure during Newton’s law of cooling experiment?
A metal ball cools at 2.0°C/min when its temperature is 60°C and the surrounding temperature is 20°C. What will be its rate of cooling when its temperature drops to 30°C?
