Question 1: Thermodynamics & KTG

Question

The figure shows the PV plot of an ideal gas taken through a cycle ABCDA. The part ABC is a semicircle and CDA is half of an ellipse. Then,
![](https://app-content.cdn.examgoal.net/fly/@width/image/1lft47k36/fdda4eba-0f59-45fb-8fe2-fcbfd6587650/0e2c3520-cde0-11ed-9ce1-7bd2ccf24231/file-1lft47k37.png?format=png)

Accepted Answer

We observe the following:
$\bullet$ For the path B $	o$ C $	o$ D, the volume (V) decreases; $\Delta$W < 0.
$\Delta U < 0 \Rightarrow \Delta Q < 0$
$\bullet$ For the process A $	o$ B $	o$ C, $\Delta$W is the area of the semicircle and $\Delta W 
e 0$.
$\bullet$ For the process A $	o$ B (semicircle), it cannot be an isothermal process (whose PV-diagram is a rectangular hyperbola).
$\bullet$ For (clockwise) process A $	o$ B $	o$ C $	o$ D $	o$ A, $\Delta$W is the area enclosed, which is positive.

Answer

the process during the path A $	o$ B is isothermal.

Answer

heat flows out of the gas during the path B $	o$ C $	o$ D.

Answer

work done during the path A $	o$ B $	o$ C is zero.

Answer

positive work is done by the gas in the cycle ABCDA.

Thermodynamics & KTG

The figure shows the PV plot of an ideal gas taken through a cycle ABCDA. The part ABC is a semicircle and CDA is half of an ellipse. Then,

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