The power factor of an RLC circuit is defined as cos = R/Z, but ...

[Chelseaamend]

The power factor of an RLC circuit is defined as cos  = R/Z, but the phase angle can also be calculated from
 
  A) sin  = (XL - XC)/Z.
  B) sin  = (XL - XC)/RZ.
  C) sin  = Z/(XL - XC).
  D) sin  = RZ/(XL - XC).

Question 2

What is the theoretical efficiency of a Carnot engine that operates between 600 K and 300 K?
 
  A) 100
  B) 75
  C) 25
  D) 50
  E) 0

[AaaA]

Answer to Question 1

A

Answer to Question 2

D