question_answer 14)

A magnetic field of is required which is uniform in a region of linear dimension about and area of crosssection about . The maximum current carrying capacity of a given coil of wire is 15 A and the number of turns per unit length that can be wound round a core is at most 1000 turns . Suggest some appropriate design particulars of a solenoid for the required purpose. Assume the core is not ferromagnetic.  

Answer:

Using we get                                                 Moreover the length of a sloenoid be much more then its diameter.                 Sincefor 15A current the number of turns per unit length of the solenoid has to be decreased.                                 i.e.                 turns per metre.