Which of the following materials has the highest value of dielectric constant?

The correct answer is: C. Ceramics

Dielectric constant is a measure of how much a material can be polarized by an electric field. Materials with a high dielectric constant are good insulators, and they are often used in capacitors.

Glass has a dielectric constant of about 4. Vacuum has a dielectric constant of 1. Ceramics have a dielectric constant of about 10 to 100. Oil has a dielectric constant of about 2 to 3.

Therefore, ceramics have the highest value of dielectric constant.