A current-carrying circular loop of magnetic moment M⃗ is suspended in a vertical plane in an external uniform magnetic field B⃗ such that its plane is normal to B⃗. The work done in rotating this loop by 45° about an axis perpendicular to B⃗ is closest to:

A charged particle is released from rest in a region of space where steady and uniform electric and magnetic fields are parallel to each other. The particle will move in a:

Two very long, straight, parallel wires carry steady currents I and 2I in the same direction. The distance between the wires is d. At a certain instant, a point charge q is at a point equidistant from the two wires in the plane of the wires. Its instantaneous velocity v is perpendicular to this plane. The magnitude of the magnetic force acting on the charge at this instant is: