Question

One of an ideal gas undergoes a cyclic process ABCDA as shown in the P-V diagram, the net work done in the process is work done in the process is (1 atm = 106 dyne cm–2)

• A. 500 J
• B. 700 J
• C. 800 J
• D. 900 J

Answer 1

Answer: (C)

800 J

Answer 2

: As the loop is traced in clockwise direction the work done is positive, Work done in the process =area of rectangle ABCD

Here, $\mathrm { AB } = 4 - 2 = 2$ litre $= 2 \times 10 ^ { 3 } \mathrm {~cm} ^ { 3 }$

Work done, $\mathrm { W } = \mathrm { AB } \times \mathrm { AD }$ $= 2 \times 10 ^ { 3 } \times 4 \times 10 ^ { 6 } = 8 \times 10 ^ { 9 } \mathrm { erg } = 800 \mathrm {~J}$