Two particles, each of positive charge q, are fixed in place on a y axis, one at y = d and the other at y = –d. Write an expression that gives the magnitude E of the net electric field at points on the x axis given by x = αd. Determine the value of α that gives (a) the maximum value of E. Determine the values of α that give half the maximum value of E. Let (b) be the lesser of the two values of α, and (c) the greater of the two values.

a solenoid is created by wrapping a l = 90 m long wire around a hollow tube of diameter d = 4.5 cm.   the wire diameter is d = 0.9 mm.   the solenoid wire is then connected to a power supply so that a current of i = 9 a flows through the wire.

randomized variablesl = 90 m

d = 4.5 cm

d = 0.9 mm

i = 9 a                                          

write an expression for the number of turns, n, in the solenoid. you do not need to take into account the diameter of the wire in this calculation.

calculate the number of turns, n, in the solenoid.

write an expression for the length of the solenoid (l2) in terms of the diameter of the hollow tube d.

calculate the length of the solenoid (l2)   in meters.

calculate the magnitude of the magnetic field at the center of the solenoid in teslas.

explanation:

i think it's 35 meters