A gear set has standard full depth involute teeth of 4 mm module with 20° pressure angle, and has 19 and (20+a) teeth, respectively on the pinion and the gear.
(i) Find the gear ratio, circular pitch, base pitch, pitch diameters, centre distance, addendum, dedendum and contact ratio of the gear set.
(ii) If the centre distance is increased by 2%, what is the new pressure angle?