Question. The surface densities on the surfaces of two charged spherical conductors of radii R1 and R2 are equal. The ratio of electric intensities on their surfaces is:
a) R12 / R22
b) R22 / R12
c) R1 / R2
d) 1 : 1
Answer: d) 1 : 1
Let the surface densities on the surfaces of two charged spherical conductors of radii R1 and R2 be σ1 and σ2 respectively.
But σ1=σ2 …(given)Electric field intensity on surface of spherical conductor is given by,
E=Q/4πϵor2=σ/ϵo
∴ Ratio of electric field intensities on their surfacesis given by,
E1/E2 = σ1/ϵo/ σ2/ϵo =σ1 / σ2 = 1/1 …(σ1=σ2)
∴E1:E2=1:1