Dhrutam always consists of two beats in Carnatic music. It is a fixed rhythmic unit, making it easy to integrate into various talams.
Class 6 Arts Kriti-I Chapter 8 Taal or Talam and Raga or Ragam in Indian Music NCERT solutions
Class 6 Visual Arts Kriti-I Taal or Talam and Raga or Ragam in Indian Music question answer