The outer sphere of a spherical air capacitor is earthed. For increasing its capacitance

  • Option 1)

    Vacuum is created between two spheres

  • Option 2)

    Dielectric material is filled between the two spheres

  • Option 3)

    The space between two spheres is increased

  • Option 4)

    The earthing of the outer sphere is removed


Answers (1)

2)Dielectric material is filled between two spheres because

In spherical Capacitor

Capacitance C, 

C = 4\pi \epsilon _{0}k\left (\frac{ab}{a-b} \right )

C\propto k

where k is dielectric constant of material between two spheres.