Applications of First Law of Thermodynamics

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Applications of First Law of Thermodynamics: Overview

This topic covers concepts, such as, Work Done in Reversible Adiabatic Process, Work Done in An Isothermal Expansion For Ideal System, Interpretation of Work from Graph of Cyclic Processes & Reversible Polytropic Process etc.

Important Questions on Applications of First Law of Thermodynamics

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During isothermal expansion of an ideal gas, its

                               

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Absolute zero is defined as the temperature

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3 moles of an ideal gas expands isothermally against a constant pressure of 2 Pascal from 20 L to 60 L.The amount of work involved is

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One mole of an ideal gas is taken from a and b along two paths denoted by the solid and the dashed lines as shown in the graph below. If the work done along the solid line path is ws and that along the dotted line path is wd, then the integer closest to the ratio wd/ws is:

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Two moles of He gas (γ=5/3) are initially at temp 27°C and occupy a volume of 20 litres. The gas is first expanded at constant pressure until its volume is doubled. Then it undergoes reversible adiabatic change, until the volume become 110 lit, then predict the value of T/100 (where T is the final temperature, 4112/3=12)

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The magnitude of reversible work done by an ideal gas in four different processes: isothermal expansion, adiabatic expansion, constant pressure expansion, and free expansion are Wi, Wa, Wp, and Wf respectively. Choose the right order of sequence for the magnitude of the work done. (Change in the volume is same for all the processes.)

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An ideal gas undergoes isothermal expansion at constant pressure. During the process:

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q, w, ΔE and ΔH for the following process ABCD for a monoatomic gas are:

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Consider the reversible isothermal expansion of an ideal gas in a closed system at two different temperatures T1 and T2 T1<T2. The correct graphical depiction of the dependence of work done w on the final volume v.

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A thermodynamic cycle in the pressure P-volume V plane is given below:
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AB and CD are isothermal processes while BC and DA are adiabatic processes. The same cycle in the temperature T- entropy S plane is :

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During the free expansion of an ideal gas in an isolated chamber,
 

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One mole of an ideal gas (at 25°C ) is expanded from volume 1 L to 4 L at constant temperature. The value of work done (in J), if gas is expanded against vacuum Pext=0?

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For next two question please follow the same

A sample of an ideal gas is expanded to twice its original volume of 1 m3 in a reversible process for which  α = 5 atm  m - 6   and  C Vm = 20 J K -1 m -1 at constant volume.

The work done during the process may be

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2 moles of an ideal gas with C Pm = 5 2 R at 1 atm, 300 K held in cylinder fitted with piston is expanded reversibly and isothermally to three times volume (initially =V). The cylinder placed in an insulated container and pressure returned to 1 atm adiabatically in one step when mechanical equilibrium is reached. Read the passage and answer the questions as single choice correct.

The volume at point C may be

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For next two question please follow the same

 2 moles of an ideal gas with CPm=52R at 1 atm, 300 K held in cylinder fitted with piston is expanded reversibly and isothermally to three times volume (initially =V). The cylinder placed in an insulated container and pressure returned to 1 atm adiabatically in one step when mechanical equilibrium is reached. Read the passage and answer the questions as single choice correct.

Δ H process may be

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Among the following, which expression is most accurate to calculate the work done by gas in reversible isothermal expansion?

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Adjacent figure shows the force-displacement graph of a moving body, the work done in displacing body from x=0m tox=35m by the shown force is equals to

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Graphically show the total work done in an expansion when the state of an ideal gas is changed reversibly and isothermally from (Pi, Vi) to (Pf. Vf). With the help of a PV plot compare the work done in the above case with that carried out against a constant external pressure Pf.

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An ideal gas is taken around the cycle ABCA as:

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Calculate work done in the cyclic process?

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P-V plots for two gases during adiabatic expansion are shown in figure. Plots 1 and plots 2 should correspond respectively to

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