In 1st case, Carnot engine operates between temperatures 300 K and 100 K . In 2nd case, as shown in the figure, a combination of two engines is used. The efficiency of this combination (in 2nd case) will be:
1
Same as the 1st case
2
Always greater than the 1st case
3
Always less than the 1st case
4
May increase or decrease with respect to the 1st case