Question

A system S receives heat continuously from an electric heater of power 10 W. The temperature of S becomes constant at 50oC when the surrounding temperature is 20oC. After the heater is switched off, S cools from 35.1oC to 34.9oC in 1 minute. The heat capacity of S is:

Solution

Correct option is

1500 J/oC

 

At 50oC,          

 

At an average temperature of 35oC,

                        

Heat lost in 1 minute = 

 

 

SIMILAR QUESTIONS

Q1

One of the most efficient engines ever developed operates between 2100 K and 700 K. Its actual efficiency is 40%. What percentage of its maximum possible efficiency is this?

Q2

In an adiabatic change, the pressure P and temperature  of a diatomic gas are related by the relation   where equals:

Q3

By opening the door of a refrigerator inside a closed room:

Q4

One mole of an ideal mono-atomic gas is heated at a constant pressure of one atmosphere from 0oC to 100oC. Then the change in the internal energy is:

Q5

One mole of an ideal mono-atomic gas is heated at a constant pressure of one atmosphere from 0oC to 100oC. The work done by the gas is:

Q6

One mole of an ideal mono-atomic gas is heated at a constant pressure of one atmosphere from 0oC to 100oC. The heat taken from the source is:

Q7

Three moles of an ideal mono-atomic gas perform a cycle as shown in figure. The gas temperatures in different states are  The work done by the gas during the cycle will be:

                                                           

Q8

Equal volumes of water and alcohol when put in similar calorimeters take 100 sec and 74 sec respectively to cool from 50oC to 40oC. The thermal capacity of each calorimeter is numerically equal to the volume of either liquid. The specific gravity of alcohol is 0.8. If the specific heat capacity of water is 1 cal/g, the specific heat capacity of alcohol will be:

Q9

During an adiabatic process at constant pressure, the temperature and volume of a gas are found to vary according to the relation TV0.4 constant. The gas should be:

Q10

A body with an initial temperature  is allowed to cool in a surrounding which is at a constant temperature of   Assume that Newton’s law of cooling is obeyed. Let k = constant. The temperature of the body after time  is best expressed by: