2. Questions Bank
  3. JEE Main & Advanced
  4. Physics
  5. Photo Electric Effect, X- Rays & Matter Waves

JEE Main & Advanced Physics Photo Electric Effect, X- Rays & Matter Waves Question Bank Matter Waves

  • question_answer
    When the momentum of a proton is changed by an amount P0, the corresponding change in the de-Broglie wavelength is found to be 0.25%. Then, the original momentum of the proton was                                   [CPMT 2002]

    A)            p0  

    B)            100 p0

    C)            400 p0                                      

    D)            4 p0

    Correct Answer: C

    Solution :

                       \[\lambda \propto \frac{1}{p}\]  Þ \[\frac{\Delta p}{p}=-\frac{\Delta \lambda }{\lambda }\]  Þ \[\left| \frac{\Delta p}{p} \right|=\left| \frac{\Delta \lambda }{\lambda } \right|\]                    Þ\[\frac{{{p}_{0}}}{p}=\frac{0.25}{100}=\frac{1}{400}\]  Þ p = 400 p0 .


You need to login to perform this action.
You will be redirected in 3 sec spinner