When the loop is the figure shown below will be rotated in clockwise direction the the slip ring connected to the red segment of the loop will give us the positive voltage and the slip ring connected to the black segment of the loop will give us negative voltage according to the Flemings right hand rule.
With the loop in that position, the induced voltage is zero so NO, there is no voltage generated at this instant or position. Reason: the induced voltage relies on rate of change of flux and with the coil vertical the flux cutting the coil may be at a maximum but the rate of change of flux is zero: -
So, using the picture above, (and considering the case from 0 degrees to 90 degrees rotating clockwise), the voltage increases to a positive peak due to the rate of change of flux (that the coil is cutting) increasing.
If you reverse direction it is the same as swapping the magnet poles and the waveform will be inverted.