3. (a) Sketch a H-B graph showing the behaviour of the following types of magnetic material: (i) Vacuum (ii) Diamagnet (iii) Paramagnet (iv) Ferromagnet (b) (v) Ferrimagnet (marks 5) Sketch the dipoles within each type of magnet given below in the cases of before and after a magnetic field has been applied. Please remember to mark on the direction of the applied magnetic field. (i) Diamagnet (ii) Paramagnet (iii) Ferromagnet (iv) Ferrimagnet (marks 4) (c) The magnetisation within a metal bar is 3 x 105 A/m when it is placed in an H field with a strength of 50 A/m. (i) Calculate the magnetic susceptibility, Xm, of the metal bar. (marks 2) (ii) Calculate the magnetic flux density within the bar. (marks 1) (iii) Suggest what type of magnet the bar is, justifying your answer. (marks 2) (d) Sketch the atomic structure of quartz and discuss how this structure gives rise to its piezoelectricity. (marks 4) (e) Briefly describe one application which uses an piezoelectric material. (marks 2)