Question

A heat engine that rejects waste heat to a sink at 510 R has a thermal efficiency of 25 percent and a second-law efficiency of 50 percent. Determine the temperature of the source that supplies heat to this engine.

Answer 1

The correct answer is "1020 K".

Step-by-step explanation:

The given values:

`n_(th) = 0,25`

`n_2=0.50`

Now,

⇒
`n_(th)(rev) = (n_(th))/(n_2)`

By putting the values, we get

`=(0.25)/(0.50)`

`=0.50`

As we know,

⇒
`n_(th) (rev)=1-(TL)/(TH)`

or,

⇒
`TH=(TL)/(1-n_(th) (rev))`

`=(510)/(1-0.50)`

`=(510)/(0.5)`

`=1020 \ K`