मराठी
कर्नाटक बोर्ड पी.यू.सी.पीयूसी विज्ञान इयत्ता ११

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? - Physics

Advertisements
Advertisements

प्रश्न

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.

बेरीज
Advertisements

उत्तर

We will prefer to seat on a wooden chair because as the conductivity of wood is poorer than that of metal, heat flow from our body to the chair will be less in case of a wooden chair.

shaalaa.com
Newton’s Law of Cooling
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 6: Heat Transfer - Short Answers [पृष्ठ ९७]

APPEARS IN

एचसी वर्मा Concepts of Physics Vol. 2 [English] Class 11 and 12
पाठ 6 Heat Transfer
Short Answers | Q 5 | पृष्ठ ९७

संबंधित प्रश्‍न

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


A body cools down from 65°C to 60°C in minutes. It will cool down from 60°C to 55°C in


Answer the following question.

State Newton’s law of cooling and explain how it can be experimentally verified.


A metal sphere cools from 80 °C to 60 °C in 6 min. How much time with it take to cool from 60 °C to 40 °C if the room temperature is 30 °C?


A bucket full of hot water cools from 85 °C to 80 °C in time T1, from 80 °C to 75 °C in time T2 and from 75 °C to 70 °C in time T3, then ______.


A liquid with a certain surface area takes 10 minutes to cool from 80° C to 70° C. The time taken by it to cool from 80° C to 60° C is [The surrounding temperature being 40° C] ____________.


Newton's law of cooling leads to the expression: 


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:


A cup of coffee cools from 90°C to 80°C in t minutes, when the room temperature is 20°C. The time taken for a similar cup of coffee to cool from 80°C to 60°C at a room temperature same at 20°C is ______


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 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?

  1. The rate of cooling is constant till milk attains the temperature of the surrounding.
  2. The temperature of milk falls off exponentially with time.
  3. 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.
  4. All three phenomenon, conduction, convection and radiation are responsible for the loss of heat from milk to the surroundings.

Is the bulb of a thermometer made of diathermic or adiabatic wall?


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.


According to Newton's law of cooling, the rate of cooling of the body is proportional to (Δθ), where Δθ is the difference between the temperature of the body and the surroundings, and n is equal to ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×