It is desired to construct a solenoid that will have a resistance of 6.00 (at 20°C) and produce a magnetic field of 4.00 10-2 T at its center when it carries a current of 4.80 A. The solenoid is to be constructed from copper wire having a diameter of 0.500 mm. If the radius of the solenoid is to be 1.00 cm, determine the following. (The resistivity of copper at 20°C is 1.7 10-8 ? · m.)
(a) the number of turns of wire needed to build the solenoid
_____ turns
(b) the length the solenoid should have
____ cm