A cylindrical capacitor is made of two concentric cylinders. The ...

[iveyjurea]

A cylindrical capacitor is made of two concentric cylinders. The inner cylinder has radius r1 = 4 mm, and the outer one a radius r2 = 8 mm. The common length of the cylinders is L = 150 m.
 
  What is the potential energy stored in this capacitor when a potential difference V = 4 V is applied between the inner and outer cylinder? A)
 
  9.6  10-8 J
  B)
 
  1.3  10-8 J
  C)
 
  6.3  10-8 J
  D)
 
  0.34  10-8 J
  E)
 
  4.6  10-8 J

Question 2

Consider two cylinders of gas identical in all respects except that one contains O2 and the other He. Both hold the same volume of gas at STP and are closed by a movable piston at one end.
 
  Both gases are now compressed adiabatically to one-third their original volume. Which gas will show the greater temperature increase?
  A)
 
  the O2
  B)
 
  the He
  C)
 
  Neither; both will show the same increase.
  D)
 
  It's impossible to tell from the information given.

[raenoj]

Answer to Question 1

A

Answer to Question 2

B

[iveyjurea]

Thank you!

[raenoj]

Always glad to help...