Question

Two long straight wires are parallel and carry current in the same direction. The currents are 8.0 and 12 A and the wires are separated by 0.40 cm. The magnetic field at a point midway between the wires is:_______a. 0b. 4 x 10^-4c. 8 x 10^-4d. 12 x 10^-4e. 20 x 10^-4

Answer 1

A magnetic field is a mathematical description of the magnetic influence of electric currents and magnetic materials. The magnetic field at any point is specified by two values, the direction and the magnitude; such that it is a vector field. Mathematically it is described as,

`B = (\mu_0 I)/(2\pi d)`

Here

`\mu_0`= Permeability at free space constant

`I_(1,2)`= Current at each object

d = Distance to the center point of the two object

Two magnetic field due to the current in the same directions then is,

`B = (\mu_0 I_1)/(2\pi d_1)+(\mu_0 I_2)/(2\pi d_2)`

Replacing,

`B = ((4\pi *10^(-7))(8))/(2\pi (2*10^(-3)))+((4\pi *10^(-7))(12))/(2\pi (2*10^(-3)))`

`B = 8*10^(-4) +12*10^(-4)`

`B = 20*10^(-4)T`

Therefore the correct answer is E.