De Broglie Wavelength Kinetic Energy — the NEET Physics formula with its derivation, variables, validity constraints and worked solver.
de Broglie Wavelength (Kinetic Energy) Valid for microscopic massive particles (electrons, protons, neutrons) moving at non-relativistic speeds. According to de Broglie hypothesis, = h/p. Classical relation between Kinetic Energy (K) and momentum (p) is K = p 2 / (2m). Rearranging for p gives p = 2mK . Substitute p into the wavelength equation to get = h / 2mK . The velocity of the particle must be non-relativistic (v << c). Kinetic Energy (K) must be converted to Joules if given in eV before substituting h in SI units. Substituting Kinetic Energy in eV directly into the formula without converting to Joules. Using this formula for photons (photons have no mass, K=hf relationship applies differently). Assuming the mass 'm' changes with speed (only valid for rest mass in non-relativistic limit).