The given figure shows the T-s diagram of Otto cycle.
Which of the following is an INCORRECT expression of the air-standard efficiency of the Otto cycle? [Where T1, T2, T3,T4 are the absolute temperatures at the state of 1, 2, 3, 4, respectively.]
1
\(\eta_{t h}=1-\frac{T_{4}}{T_{3}}\)
2
\(\eta_{t h}=1-\frac{T_{1}}{T_{4}}\)
3
\(\eta_{t h}=1-\frac{T_{4}-T_{1}}{T_{3}-T_{2}}\)
4
\(\eta_{t h}=1-\frac{T_{1}}{T_{2}}\)