Explanation:
The given data is as follows.
[tex]T_{c} = 25^{o}C[/tex], [tex]T_{h} = 350^{o}C[/tex]
Work produced per kJ of heat extracted from hot reservoir = 0.45 kJ = Efficiency
If the device is Carnot cycle then its efficiency will be maximum and its value will be equal to [tex][1 - (\frac{T_{c}}{T_{h}} )][/tex]
Using this relation we will calculate the efficiency as follows.
Efficiency = [tex][1 - (\frac{T_{c}}{T_{h}} )][/tex]
= [tex]1 - (\frac{25}{350})[/tex]
= 0.928
Hence, it means that this type of device is possible and the claim is also believable.