Task: Text Categorization
Input (English): Particles of dielectric materials may be separated in a fractionation method that uses a nonuniform one of these. Band-bending occurs because it varies linearly in a depletion layer. Symmetric top molecules undergo line-splitting in their microwave spectrum due to the application of one of these. Modulators for active Q-switching lasers rely on an effect in which crystals lacking inversion symmetry become birefringent in linear proportion to the magnitude of one of these. Its flux through a surface is proportional to enclosed charge, and its curl is equal to the negative time partial of the magnetic field. Its magnitude is proportional to one-over-r for a line charge, and it is proportional to one over r squared for a point charge. For 10 points, name this vector field given in units of volts per meter.
Output (English): Science