Final answer:
The mudra known as the mudra of knowledge is the Gyan Mudra or Jnana Mudra, which represents wisdom, understanding, and the readiness for spiritual learning.
Step-by-step explanation:
The mudra that is also known as the mudra of knowledge is often referred to as the Gyan Mudra or Jnana Mudra. In this gesture, the thumb and index finger touch to form a circle, representing the wheel of law and the unification of the divine with the individual soul. It is traditionally associated with wisdom, understanding, and an expansion of consciousness, symbolically conveying the practitioner's readiness for spiritual learning and the acquisition of true knowledge.