Is the Current of A Full Wave Bridge Rectifier Roughly Constant?
For a diode bridge with no smoothing capacitor, the instantaneous current on the AC side MUST equal the magnitude of the instantaneous current on the DC side.


  if the input is .5A AC input will the output be .5A DC output?


No that isn't quite true - the RMS currents will be equal i.e. produce the same power when feeding a resistor of the same value. The "DC output" could be taken as meaning the average output from the rectifier and this won't equal the RMS of the input current to the bridge.