Q 1 :    

The capacitance of a parallel plate capacitor with air as medium is 6 μF. With the introduction of a dielectric medium, the capacitance becomes 30μF. The permittivity of the medium is (ε0=8.85×10-12C2N-1m-2)            [2020]
 

  • 0.44×10-13C2N-1m-2

     

  • 1.77×10-12C2N-1m-2

     

  • 0.44×10-10C2N-1m-2

     

  • 5.00C2N-1m-2

     

(3)

Given: capacitance without dielectric, C=6 μF and capacitance with dielectric, C'=30μF.

    Dielectric constant, K=C'C=306=5.

Now, permittivity of the medium, ε=Kε0

=5×8.85×10-12=0.44×10-10C2N-1m-2



Q 2 :    

Two thin dielectric slabs of dielectric constants K1 and K2(K1<K2) are inserted between plates of a parallel plate capacitor, as shown in the figure. The variation of electric field E between the plates with distance d as measured from plate P is correctly shown by         [2014]

  •  

  •  

  •  

  •  

(3)

Emedium=EvacuumK

The electric field inside the dielectrics will be less than the electric field in vacuum. The electric field inside the dielectric could not be zero. As K2>K1, the drop in electric field for K2 dielectric must be more than K1.