It is desired to construct a solenoid that has a resistance of 9.29 ohm and produces a magnetic field at its center of 0.0642 T when it carries a current of 7.32 A. The solenoid is to be constructed from copper wire having a diameter 0.895 mm. The resistivity of the copper is 1.7x10-8 ohm-m. Find the # of turns of wire needed if the radius of the solenoid is to be 1.26 cm. Answer in units of turns. Find the length of the solenoid. Answer in units of cm. This is what I did: B=N x muI/2R .0642=N x (4pi x 10-7)(7.32)/(2*.0126) N=175.879 turns ...But this is wrong. Can you please help me out & let me know what I did wrong? Find the length of the solenoid. Answer in units of cm. I used: R=pl/A 9.29=1.7x10-8(l)/(.000895/2)^2 *pi l=34379.8 cm ...I think this one is wrong too. Any help would be appreciated! Thanks in advance!!