Commonly used standard capacitor is

spherical type
concentric cylindrical type
electrostatic type
multilayer parallel plate type

The correct answer is: D. multilayer parallel plate type.

A capacitor is an electrical device that stores energy in an electric field. It is made up of two conductive plates separated by an insulating material, called the dielectric. The capacitance of a capacitor is measured in farads (F).

The most commonly used type of capacitor is the multilayer parallel plate capacitor. It is made up of multiple layers of conductive plates separated by dielectric material. The plates are arranged in parallel, and the dielectric material is sandwiched between them. The capacitance of a multilayer parallel plate capacitor is proportional to the area of the plates, the distance between the plates, and the permittivity of the dielectric material.

Spherical capacitors are less common than multilayer parallel plate capacitors. They are made up of two spherical conductors separated by an insulating material. The capacitance of a spherical capacitor is proportional to the radius of the spheres and the permittivity of the dielectric material.

Concentric cylindrical capacitors are also less common than multilayer parallel plate capacitors. They are made up of two concentric cylinders separated by an insulating material. The capacitance of a concentric cylindrical capacitor is proportional to the radius of the cylinders and the permittivity of the dielectric material.

Electrostatic capacitors are the oldest type of capacitor. They are made up of two conductive plates separated by a small air gap. The capacitance of an electrostatic capacitor is proportional to the area of the plates and the permittivity of free space.

Multilayer parallel plate capacitors are the most commonly used type of capacitor because they are small, lightweight, and have a high capacitance. They are used in a variety of applications, including power supplies, filters, and oscillators.