Question

Consider a thin, spherical shell of radius 12.0 cm with a total charge of 34.8 µC distributed uniformly on its surface.

(a) Find the electric field 10.0 cm from the center of the charge distribution.

magnitude	MN/C
direction	---Select--- radially inward radially outward the electric field is zero

(b) Find the electric field 22.0 cm from the center of the charge distribution.

magnitude	MN/C
direction

Answer 1

Part A.

Given that charge on the surface of conducting spherical shell is Q = 34.8*10^-6 C

Radius of spherical shell = 12.0 cm = 0.12 m

Since charge is distributed uniformly on the surface of spherical shell, So net charge inside the shell is zero.

Now Electric field is given by:

E = k*q/r^2

for r = 10.0 cm = 0.1 m, (r < R), So net charge inside the shell is zero, which means

E = k*0/r^2 = 0 MN/C

Magnitude of electric field = 0 MN/C

Direction = the electric field is zero.

Part B.

When r = 22.0 cm = 0.22 m (r > R), So at this point electric field will be given by:

E = k*Q/r^2

E = 9*10^9*34.8*10^-6/0.22^2

E = 6.47*10^6 N/C

Since 1*10^6 N/C = 1 MN/C, So

E = magnitude of electric field = 6.47 MN/C

Direction = radially outward

Direction of electric field is away from positive charge and towards the negative charge, So since in this case charge is positive, which means electric field is away from charge radially outward

Let me know if you've any query.