Two conducting hollow spheres are are placed concentrically, the inner sphere have a radius ra = 5 cm and the outer sphere have a radius rb = 15 cm. The charge on the inner sphere is qa = 4 · 10−7 C and qb = −4 · 10−7 on the outer sphere.
(a) Use Gauss’s law to find the electric field outside the two spheres, r > rb.
(b) Use Gauss’s law to find the electric field inside the inner sphere, r < ra.
(c) Use Gauss’s law to find an expression for the electric field between the two spheres, ra ≤ r ≤ rb
The Attempt at a Solution
I tried to use the formula E*dA=Q/e0 but from what i got on from a and b is that q=0 in both the problems am i doing anything wrong? Q in problem a is Qa+Qb=0 and in problem b, because it is inside the sphere Q will always be 0