An air-filled capacitor is formed from two long conducting cylindrical shells that are coaxial and have…

An air-filled capacitor is formed from two long conducting
cylindrical shells that are coaxial and have radii of 21mm and 108
mm. The electric potential of the inner conductor with respect to
the outer conductor is – 400 V (k = 1/4πε
0 = 8.99 × 109 N ·
m2/C2) The energy stored in a 1.0-m length of
this capacitor is closest to
5.5 μJ.
2.7 μJ.
1.9 μJ.
7.6 μJ.
3.8 μJ.