What resistance must be put in series with a 30-mH inductor at ...

[Evvie72]

What resistance must be put in series with a 30-mH inductor at 4000 Hz to have a total impedance of 8.0  104 ?
 
  A) 30  104
  B) 5.0  104
  C) 6.0  104
  D) 7.0  104
  E) 8.0  104

Question 2

A moving object's mass is twice its rest mass. Its length (in the direction of travel) must therefore be
 
  A) one-half its proper length.
  B) twice its proper length.
  C) one-fourth its proper length.
  D) four times its proper length.
  E) times its proper length.

[thall411]

Answer to Question 1

E

Answer to Question 2

A