Task: Text Categorization
Input (English): The reactance of an inductor is equal to this quantity times the inductance, and resonance occurs at the natural type of this quantity. Beats occur two waves have very close values for this quantity. High-energy waves like gamma rays have higher values for this quantity, since the energy is equal to h-bar times this quantity. The Doppler effect results in a shift in this quantity which is measured in Hertz and which is equal to the number of oscillations per second. For 10 points, name this quantity equal to velocity divided by wavelength that has units of one over time.
Output (English): Science