Prakas Chandra Bhowmik's seminar paper discusses different types of insulators used in power transmission and distribution systems. The paper describes five main types of insulators - pin, suspension, strain, stay, and shackle insulators - and their applications in low and high voltage power lines. It also covers the properties, testing, failure causes, and applications of insulators. In conclusion, the paper provides a brief overview of the different insulator types used in overhead transmission lines and their specific uses.