Question

In the picture below, the two wires carry current i₁ and i₂, respectively, with positive current to the right. The charge q is positive and has velocity v to the right.

True or False: If i₁ = - i₂, then the wires repel each other.
True or False: If i₂ = - i₁ then the force on q equals zero.
True or False: If i₁ = 0 and i₂ is greater than zero, then the magnetic field near charge q points into the page.
True or False: If i₂ = 0 and i₁ is greater than zero, then the force on q points into the page.
True or False: If i₁ is greater than i₂, then the force on q is north.
True or False: If i₂ = 0 and i₁ is greater than zero, then the force on q is north.
True or False: If v = 0, then the force on q is zero.

Answer 1

Using Flemming's right hand rule:
positive current to the right
positive charge velocity v to the right

If i1 = - i2, then the wires repel each other - True

If i2 = - i1 then the force on q equals zero - False

If i1 = 0 and i2 is greater than zero, then the magnetic field near charge q points into the page. - False

If i2 = 0 and i1 is greater than zero, then the force on q points into the page.- False

If i1 is greater than i2, then the force on q is north. - True.

If i2 = 0 and i1 is greater than zero, then the force on q is north. - True

If v = 0, then the force on q is zero. - True.