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

  • question_answer
    Assertion             :       Kinetic energy of photo electrons emitted by a photosensitive surface depends upon the intensity of incident photon. Reason                 :   The ejection of electrons from metallic surface is possible with frequency of incident photon below the threshold frequency. [AIIMS 1999]

    A)             If both assertion and reason are true and the reason is the correct explanation of the assertion.

    B)             If both assertion and reason are true but reason is not the correct explanation of the assertion.

    C)             If assertion is true but reason is false.

    D)             If the assertion and reason both are false.

    E)             If assertion is false but reason is true.

    Correct Answer: D

    Solution :

                According Einstein equation \[KE=h\nu -h{{\nu }_{0}};\] i.e., KE depends upon the frequency. Photoelectron emitted only if incident frequency more than threshold frequency.


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