A real (non-Carnot) thermodynamic engine, operating between ...

[magmichele12]

A real (non-Carnot) thermodynamic engine, operating between thermal energy reservoirs at temperatures of 450 K and 270 K, performs 3.3 kJ of net work, and rejects 8.2 kJ of energy in a single cycle.
 
  (a) What is the thermal efficiency of this thermodynamic engine? (b) What is the maximum efficiency it could possibly have?

Question 2

A 360-nm thick oil film floats on the surface of a pool of water. The indices of refraction of the oil and the water are 1.50 and 1.33, respectively.
 
  When the surface of the oil is illuminated from above at normal incidence with white light, what is the wavelength of light between 400 nm to 800 nm wavelength that is most weakly reflected?
  A) 520 nm
  B) 540 nm
  C) 560 nm
  D) 580 nm
  E) 600 nm

[vish98]

Answer to Question 1

(a) 0.29 (b) 0.40

Answer to Question 2

B

[magmichele12]

Excellent

[anyusername12131]

Gracias!