How to test a xenon flash tube of a nikon dslr D5100 camera?

How to test a xenon flash tube of a nikon dslr D5100 camera?

In a dimly lit room:
Set the camera to manual
Set shutter speed to 1/100th
Set aperture to f/5.6
Set ISO to 400
Activate the flash
Take a shot of an object 3 metres away.
Did the flash fire?
Is the exposure correct?
If the answer to the last 2 questions is "yes" then it is working; "no" to both or either and it is not working.