Why do electric charges that move through a magnetic field produce an electric current? A. The magnetic field exerts a force on only the negative charges in the wire. B. The magnetic field pushes negative charges and positive charges in opposite directions. C. The magnetic field pushes negative charges and positive charges in the same direction. D. The magnetic field exerts a force on only the positive charges in the wire.

The chemical effect of the endocrine system is longer lasting than the chemical effect of the nervous system. select the best answer from the choices provided t f

Consider a uniformly charged ring in the xy plane, centered at the origin. the ring has radius a and positive charge qdistributed evenly along its circumference. a)what is the direction of the electric field at any point on the z axis? . b)what is the magnitude of the electric field along the positive z axis? use k in your answer, where k=14πϵ0. d)the ball will oscillate along the z axis between z=d and z=−d in simple harmonic motion. what will be the angular frequency ω of these oscillations? use the approximation d≪a to simplify your calculation; that is, assume that d2+a2≈a2. express your answer in terms of given charges, dimensions, and constants

Where do magnetic lines of force enter earth?