निम्नलिखित में से कौन सा ध्रुवीय आकृति मापांक (polar section modulus - Zp) के सूत्र को सही ढंग से दर्शाता है? (जहाँ J ध्रुवीय जड़त्व आघूर्ण है और c शाफ्ट की त्रिज्या है)

The most economical section of a shaft subjected to pure torsion is:

In a shaft system with equal lengths and a common angle of twist, the torque is divided between two parallel shafts based on the:

If T = Torque, J = Polar moment of inertia, C = Modulus of rigidity, θ = Angle of twist, and L = Length of the shaft, which of the following is the correct torsional equation?