Which of the following statements are true? check all that apply.
a) the electric field between the plates of a parallel-plate capacitor is uniform.
b) a capacitor is a device that stores electric potential energy and electric charge.
c) the capacitance of a capacitor depends upon its structure.
d) a capacitor consists of a single sheet of a conducting material placed in contact with an insulating material.

Answers.
a. The electric field between the plates of a parallel capacitor is uniform
b. A capacitor is a device that stores potential energy and electric charges.
c. The capacitance of a capacitor depends upon its structure.

Explanation
Capacitor is a device that is used to store electric charge. The capacitance that can be stored in a capacitor depend on area of overlap of the plates, dielectric used and distance between the two plates of a parallel capacitor.
From the choices given in the question the one that applies are:
a. The electric field between the plates of a parallel capacitor is uniform
b. A capacitor is a device that stores potential energy and electric charges.
c. The capacitance of a capacitor depends upon its structure.