A wire carries a current of 6.91 A in a direction that makes an angle of 19◦ with the direction of a magnetic field of strength 0.289 T. Find the magnetic force on a 6.7 m length of the wire. Answer in units of N.

4.454 N.

Explanation:

The force on a current carrying conductor in a magnetic field is given as,

F = BILsinФ Equation 1

Where F = magnetic Force, B = magnetic Field, I = current, L = Length of the wire, Ф = The angle between the conductor and the Field.

Given: B = 0.289 T, I = 6.91 A, L = 6.7 m, Ф = 19°

Substitute into equation 1

F = 0.289(6.91)(6.7)sin19

F = 0.289×6.91×6.7×0.33

F = 4.454 N.

Hence the magnetic force = 4.454 N.

the working equation for the angular size is the product of the physical size and 360 degrees divided by the product of two pi and distance from earth. the minimum size would be 0.559 degrees while the maximum size would be 0.49 degrees. 

probably not if net force is zero