The test I took at regionals last year was mostly objective. There's some math, identifying harmonic modes, refraction, math, identifying parts of a wave (amplitude, period, etc.), and math.
The states test was a station based test, like "Shine the flashlight through the comb onto the mirror. Identify and draw its ray of light, the mirror backing, and its reflection. How does the angle of incidence compare to the angle of reflection?" and "Shine the flashlight through the red and green paddles (translucent plastic things) and tell me what color it makes." I could answer half of the test without actually BEING at the station.
I don't know about practice tests, though questions like finding frequency, wavelength, or speed would be good practice. And always, bring a calculator!
Dual-Booting Windows 7 and Ubuntu 9.10
"Mentat, solve thyself." ~ Dune
I follow the Path of the Beam.