Asolenoid is made from a copper wire that is 15 m long and has a radius of 1.6 mm. the resistivity of copper is 1.68 x 10-8 ωm. to form the solenoid, the copper wire is tightly wrapped around a tube that is 0.35 m long and has a diameter of 2.5 cm. the solenoid is connected to a power source which supplies an emf of 2.5 v. find the magnitude of the magnetic field through the center of this solenoid.