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Direction (Q. Nos. 23) A parallel plate capacitor is as shown in figure. Half of the region in between the plates of the capacitor is filled with a dielectric material of dielectric constant K and in the remaining half air is present. The capacitor is given a charge Q with the help of a battery. Some surfaces are marked on the figure.

Surface I is the right half inner surface of the upper plate of capacitor in tire region in which air is present.

Surface II is the left half inner surface of the upper plate of capacitor.

Surface III is the surface of the dielectric slab which is near to the upper plate of capacitor.

Based on above information answer the following questions:

Mark out the correct statement(s).

A)  The electric field in region with dielectric is greater than that of electric field in the air-filled region.

B)  The electric field in the region with dielectric is less than that of electric field in the air-filled region.

C)  The electric field in the region with dielectric is equal to that of electric field in the air-filled region.

D)  Nothing can be predicted about electric field from the given information.

Correct Answer: C

Solution :

 The two halves of the capacitor can be considered as two capacitors in parallel having capacitances of \[K{{C}_{0}}\] and \[{{C}_{0}},\] where \[{{C}_{0}}\] is the capacitance of air-filled part of capacitor. As the two capacitors are connected in parallel, so the potential difference across these two capacitors are same and as separation between the plates of both the capacitors are some so the electric field in between the plates of both capacitors would be the same