question_answer 45)

  An electron (mass m) with an initial velocity  is in an electric field If it?s de Brogue wavelength at time is given by (a)                                    (b) (c)                 (d)

Answer:

  (c)Initial de-Broglie wavelength of electron, Force on electron in electric field,  Acceleration of electron, It is acting along negative y-axis.                                                                 The initial velocity of electron along- -axis u Initial velocity of electron along y -axis, Velocity of electron after time t along x-axis, (there is no acceleration of electron along axis) Velocity of electron after time t along y-axis, Magnitude of velocity of electron after time t is De ? Broglie wavelength,