I am going through the below link for understanding transmission line reflections.

The below figure is an equivalent circuit of an open-ended transmission line. For finding the voltage at V+ why the author used voltage division.

This is an open-ended transmission line so the voltage at V+ should be the open-circuit voltage Vg?

May I know where I went wrong?

https://incompliancemag.com/article/transmission-line-reflections-at-a-resistive-load/

Regards