A spherical shell of radius R = 1.5 cm has a charge q=20μC uniformly distributed over it. The force exerted by one half over the other half is
zero
10−2N
500 N
2000 N
E=σ2ε0F=Edq=σdAσ2ε0P=FdA=σ22ε0
Force =PπR2=σ22ε0πR2=Q216π2R4πR22ε0=Q232πε0R2=20×10−62×9×10981.5×10−22=2000N