
$(A)$ With a node at $O$, the minimum frequency of vibration of the composite string is $v_0$
$(B)$ With an antinode at $O$, the minimum frequency of vibration of the composite string is $2 v_0$
$(C)$ When the composite string vibrates at the minimum frequency with a node at $O$, it has $6$ nodes, including the end nodes
$(D)$ No vibrational mode with an antinode at $O$ is possible for the composite string
$(a)$ Every particle has a fixed amplitude which is different from the amplitude of its nearest particle.
$(b)$ All the particles cross their mean position at the same time.
$(c)$ All the particles are oscillating with same amplitude.
$(d)$ There is no net transfer of energy across any plane.
$(e)$ There are some particles which are always at rest.
Which of the following is correct