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(a) i) Write the Ohm's law in its microscopic and macroscopic form. ii) Describe briefly the main difference of the two forms of the Ohm's law in i). iii) Define electromotive force emf, & in an electric circuit. (b) The motional em f, & is generated due to the motion of a wire of length 1 with uniform velocity v in static magnetic field B. i) With the aid of an appropriate diagram describe how the magnetic field B generates the emf, E. ii) It is well known that the magnetic force does not do any work. Explain how the emf in part i) is actually generated. (c) i) Describe briefly the possible problem with the Ampere's law prior to the introduction of the Maxwell's displacement current. ii) With the aid of an appropriate diagram describe how the displacement current solves the problem related to the charging of a capacitor. iii) Using an appropriate diagram show that the normal components of the magnetic field B are always continuous across an interface of two media.