Question

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:

                                                           

Solution

Correct option is

20 kJ

 

Figure shows that on segments, 1–2 and 3–4, pressure is directly proportional to the temperature. It follows from ideal gas equation that gas volume remains unchanged in this case and the gas does no work. So we must find the work done only in isobaric processes 2–3 and 4–1. The work

      

Total work done by the gas during the cycle is:

             

The equation of state for three moles of ideal gas:

              

               

Putting these values, we get:

               

SIMILAR QUESTIONS

Q1

Find the  amount of work done to increase the  temperature of one mole of ideal gas by 30oC, if it is expanding under the condition  (R = 8.31 J/mol-K):

Q2

For an adiabatic expansion of a perfect gas, the value of  is equal to:

Q3

In an adiabatic expansion of a gas, the product of pressure and volume:

Q4

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?

Q5

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

Q6

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

Q7

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:

Q8

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:

Q9

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:

Q10

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: