Please attach your spice file. It is hard to read from the picture.
It looks like the switching frequency is at resonant with C1 L1.
24V square wave to sign wave 100Vp-p? That is more voltage than I would expect.
No wrong thought.
48V p-p square wave. In my head I was thinking 70 volts p-p.
I don't have an answer.
The title is rather misleading! It is an H-Bridge switch driving what may be a resonant transformer to supply a full wave bridge rectifier.
And this looks a lot like an end of term exam problem, probably second year level. I did not go thru the rather tedious arithmetic to get an answer.