1. EMF produced  is directly proportional to the magnetic flux induced. ie the amount of voltage induced is directly proportional to the magnetic field produced.
2. We should a high emf . The more the number of coils the greator the static magnetic field around it thusincreasing the amount of E.M.F induced.
3.In the graph the coil is entering the magnet when the cosine curve is negative of the y-axis while it leaves when the graph is at positive of both y and x axis.
4.Because there is varying of the induction of the second peak the coil is leaving the magnet while that of the first is entering the coil.
5 Because at the centre of the magnet there is cancelation of the osciliation. In normal induction the magnet moves like a pendulum to and fro thus inducing some current.
6.Number of coils: The greator the number of the coils the more the emf is induced. Angle between the induced material and the magnet at an angle of 90 degrees there is maximum induction and at an angle of zero the induction is least.