Task: Text Categorization
Input (English): The real part of the Clausius-Mossoti factor determines the direction of the force exerted by this. The Wannier-Stark problem involves exactly solving the Schrodinger equation for a single electron in a crystal subjected to a constant, external one of these. By Faradays Law of Induction, the partial time derivative of the magnetic field is equal to the curl of this. Nonuniform ones can induce dielectrophoresis, and the integral of it with respect to distance is electrical potential. For 10 points, name this field that surrounds point charges, denoted E.
Output (English): Science