 #1
hidemi
 208
 36
 Homework Statement:

The diagram shows one plate of a parallelplate capacitor from whin the capacitor. The plate is circular and has radius R. The dashed circles are four integration paths and radii of r1=R/4, r2=R/2, r3=3R/2, and r4=2R. Rank the paths according to the magnitude of ∫B.ds
around the paths during the discharging of the capacitor, least to greatest.
A) 1, 2 and 3 tie, then 4
B) 1,2,3,4
C) 1, then 2 and 4 tie, then 3
D) 4,3,1,2
the answer is C
E) all tie
 Relevant Equations:
 B = μ0*I / 2πr
My calculation is as attached. Where am I wrong?