fixing typo

Chapter_9/capacitor.py

@@ -31,11 +31,11 @@ def V(x,y, z0 = 1, Q = 1, L = 10):
     return integral(vz,0,2*z0,precision = 1e-2,silent = False)
 
 
-distance = 0.2
+distance = 0.1
 
 
-potential = V(0,0,distance/2)
-theory = distance*4*math.pi
+potential = V(0,0,distance)
+theory = distance*8*math.pi
 print("In the center : potential = {} - theory = {};  diff = {:.2f}%".format(potential,theory, 200*(potential-theory)/(potential + theory)))