Question 958: Thermodynamics & KTG

Question

A system is taken from state a to state c by two paths adc and abc as shown in the figure. The internal energy at a is $${U_a} = 10\,J$$. Along the path adc the amount of heat absorbed dQ
1
$$=$$ 50 J and the work obtained dW
1
$$=$$ 20 J whereas along the path abc the heat absorbed dQ
2
= 36 J. The amount of work allong the path abc is

Accepted Answer

From first law of thermodynamics
$${Q_{adc}} = \Delta {U_{adc}} + {W_{adc}}$$
$$50\,J = \Delta {U_{adc}} + 20J$$
$$\Delta {U_{adc}} = 30J$$
Again
$${Q_{abc}} = \Delta {U_{abc}} + {W_{abc}}$$
$${W_{abc}} = {Q_{abc}} - \Delta {U_{abc}}$$
$${W_{abc}} = 36\,J - 30\,J$$
$${W_{abc}} = 6\,J$$

Answer

10 J

Answer

12 J

Answer

36 J

Answer

6 J

Thermodynamics & KTG

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