Answer to Question #52087 in Field Theory for vi

Question

An engine absorbs 2000J of heat from a hot reservoir and expels 750J to a cold reservoir during each operating cycle. How much work is done during the cycle?
1250J
750J
2000J
350J

15 An engine absorbs 2000J of heat from a hot reservoir and expels 750J to a cold reservoir during each operating cycle. What is the efficiency of the engine?
50%
62.5%
74.2%
85.6%

16 Calculate the work done on the system when 1.00 mol of gas held behind a piston expands irreversibly from a volume of
1.00dm3
to a volume of
10.0dm3
against an external pressure of 1.00 bar.
-900 J
-1800 J
-1900 J
-60 J

17 A perfect gas expands reversibly at a constant temperature of 298 K so that its volume doubles. What is the change in the molar internal energy of the gas?
−0.125Jmol−1
0Jmol−1
983Jmol−1
1Jmol−1