Question

explain why the presence of dielectric increases the capacitance of the capacitor ​

Answer 1

when dielectric is introduced in the conductor plates of a capacitor ,electric field inside a dielectric decreases more charge can now be given to the capacitor to maintain the same electric field or the capacitor can now hold more charge since capacitance is directly proportional to the charge for a constant potential the capacitor is increased

Answer 2

When a dielectric slab is introduced between the two plates of a parallel plate capacitor, the electric field is reduced and the capacitance of a capacitor is increased by K times.

i.e., Cm=KC0 where Cm is capacity of capacitor with dielectric medium introduced in it and C0= capacity of capacitor without dielectric and K is the dielectric constant.