Consider two positive charges separated by a distance ((A 20)/100) meters. One charge has a value of (B 5) mC (milli-coulombs) and is located to the right of the other (C 5) mC charge. Assume the left charge is the origin and the other charge is located with a positive horizontal position. How large and in what direction is the electrostatic field at the mid-point, directly between the two charges

E_total = 0

Explanation:

In this exercise we are asked for the electric field created by two charges at the midpoint between them, since the electric field is a vector magnitude it must be added as vectors. The equation that describes the electric field for a charge is

in this case the two charges are positive, therefore the field is salient, in the adjoint we can see a diagram of the system

          E_total = E₁ -E₂

we calculate the electric field of charge 1 with q = + 5 10⁻³ C and a distance r = L / 2 = 100/2 = 50 m

           E₁ =

           E₁ = 1.8 10⁴ N / C

the magnitude of the electric field of charge 2 is equal, but the sense is opposite.

Since the two charges have the same sign, the addition of vectors gives zero

           E_total = 0

if the charges were of different signs, the fields would be added

            E_total = 3.6 10⁴ N / A

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: