i have ner seen a sample of this test, but i think it will have a lot to do with what its name implies 'rotating equipment start up'. So my advice is read things on compressor,pumps and gas turbine systems. they various start-up and auxilliary systems. ignition, lubrication, troubleshooting and maintenance sequence. I think they must ask what the start up sequence for a particular equipment is? i.e step by step what to do b4 starting. Checks to be carried out, speeds, etc. basic details.
Like i said i have never taken such test, but this is what i woul've prepared.
May i ask how u got the invite? are u a fresh graduate or experienced? thanks