The correct answer is B.
A capacitor is a device that stores electrical energy in an electric field. It consists of two conductive plates separated by an insulating material, called the dielectric. The capacitance of a capacitor is a measure of its ability to store electrical energy. It is proportional to the area of the plates, the permittivity of the dielectric, and inversely proportional to the distance between the plates.
Bakelite is a type of plastic that is a good insulator. When a sheet of bakelite is inserted between the plates of an air capacitor, the dielectric constant of the capacitor increases. This increases the capacitance of the capacitor.
The other options are incorrect because:
- Option A is incorrect because the capacitance of a capacitor increases when the dielectric constant of the dielectric increases.
- Option C is incorrect because the capacitance of a capacitor decreases when the distance between the plates increases.
- Option D is incorrect because the capacitance of a capacitor cannot become zero.