A metallic spherical shell has an inner radius of 5.80 cm and an outer radius of
ID: 1611426 • Letter: A
Question
A metallic spherical shell has an inner radius of 5.80 cm and an outer radius of 9.00 cm . The surface charge density on the inner surface is -100 nC/m2 while the surface charge density on the outer surface is +100 nC/m2 . The image shows a cross section of the metallic shell.(Figure 1)
Part A
What is the strength of the electric field at point 4 cm from the center?
Part B
What is the direction of the electric field at point 4 cm from the center?
Part C
What is the strength of the electric field at point 8 cm from the center?
Part D
What is the direction of the electric field at point 8 cm from the center?'
Part E
What is the strength of the electric field at point 12 cm from the center?
Part F
What is the direction of the electric field at point 12 cm from the center?
Metallic Ring Router RinnerExplanation / Answer
Surface area for inner sphere = 4**(5.8*10-2)2
Charge on inner surface = 4**(5.8*10-2)2 * - 100 nC = - 4.227 nC
Q = 4.227 nC
Charge on outer surface = q
q = 4**(9*10-2)2 * 100 nC = 10.18 nC
a) Electric field at r = 4 cm
E = kQ/r^2 = 9e9*4.227*10^-9/0.04/0.04
E = 23.78 kN/C
b) outside
c) Electric field at r = 8 cm
inside the metal there will be no electric field ( being a conductor)
E = 0
d) no direction
e) Electric field at r = 12 cm
E = kq/r^2 = 9e9*10.18e-9/0.12/0.12
E = 6.36 kN/C
f) outside