Thermodynamics Part 2

Efficiency of Carnot heat engine is given by
η=1−‌

T2

T1

=1−‌

Q2

Q1

=‌

W

Q1

.....(i)
where. W= net work done by the gas
Q1= heat absorbed by the gas,
Q2= heat released by the gas,
T1= temperature of hot reservoir,
and T2= temperature of cold reservoir.
Using Eq. (i), we can write
1−‌

T2

T1

=‌

W

Q1

⇒‌

T2

T1

=1−‌

W

Q1

⇒‌‌‌

400

800

=1−‌

W

Q1

⇒‌

W

Q1

=1−‌

400

800

⇒‌‌‌

W

Q1

=1−‌

1

2

=‌

1

2

⇒‌

W

Q1

=‌

1

2

⇒‌‌Q1=2×W=2×1200[∵W1=1200J]
=2400J