Question

figure below shows two paths that may be taken by a gas to go from a state A to a state C. In process AB, 400 J of heat is added to the system and in process BC, 100 J of heat is added to the system. The heat absorbed by the system in the process AC will be:

• A. 460 J
• B. 300 J
• C. 380 J
• D. 500 J

Answer 1

Answer: (A)

460 J

Answer 2

In cyclic process ABCA,
$\Delta {U_{cyclic}} = 0$
${Q_{cyclic} = W_{cyclic}}$
${Q_{AB} = Q_{bc} + Q_{CA} =}$ closed loop area.

$400 + 100+ Q_{CA} = \frac{1}{2}\times (2\times 10^{-3}) \times 4\times 10^4$
${400 +100 Q_{AC = 40}}$
${Q_{AC} = 460 J}$