the capacitance of a parallel plate capacitor can be increased by either inserting insulating slab or conducting slab of thickness d/2 between the plates. Which of the two slabs will be more effective?
Answers
Dear friend the answer for this question is here:
The capacitance of a capacitor when a dielectric medium is placed between the plates is given by : C=εoA/(d-t+t/K) Where, εo is permittivity of free space, A is the area of a plate , d is the distance between the plates , t is thickness of the dielectric medium, K is dielectric constant of the medium. Now if the conductor completely occupies the space, then K=∞ and t=d Hence we get, C=∞ . Now look at the same situation in terms of the definition of capacitance i.e Q=CV . The capacitance is the ability of the plates to hold charge. But here if we connect the plates of the capacitor to the terminals of the battery , the current flows through the conducting slab ,across the plates .No charge will be accumulated on the plates . The potential difference across the plates is zero.
Hope ti helps you!!!