1) If the kinetic energy of a free electron doubles, it's de-Broglie wavelength changes by the factor A) 2 B) 12 C) √2 D) 1√2 Answer: Option DExplanation:de-Broglie wavelength, λ=hp=h√2.m.(K.E) λ∝1√K.E If K.E is doubled, then de-Broglie wavelength becomes λ√2