For a current carrying coil, flux is proportional to current ie, `phi_B alpha I`. Give the dimensions and SI unit of proportionality constant.

For a current carrying coil, flux is proportional to current ie, phi_B alpha I .________ is the constant of proportionality that appears in the above relation.

A magnetic field of 100 G (1 G = 10^(-4)T) is required which is uniform in a region of linear dimension about 10 cm and area of cross-section about 10^(-3) m^(2) . The maximum current carrying capacity of a given coil of wire is 15A and the number of turns per unit length that can be wound round a core is at most 1000 turns m^(-1). Suggest some appropriate design particulars of a solenoid for the required purpose. Assume the core is not ferromagentic.