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JEE Main & Advanced Physics Photo Electric Effect, X- Rays & Matter Waves Question Bank Self Evaluation Test - Dual Nature of Radiation and Matter

  • question_answer
    A 5 watt source emits monochromatic light of wavelength\[\text{5000 }\overset{\text{o}}{\mathop{\text{A}}}\,\]. When placed 0.5 m away, it liberates photoelectrons from a photosensitive metallic surface. When the source is moved to a distance of 1.0 m, the number of photoelectrons liberated will be reduced by a factor of

    A) 8 

    B) 16   

    C) 2

    D) 4

    Correct Answer: D

    Solution :

    [d] Number of emitted electrons \[{{N}_{E}}\propto \text{Intensity}\propto \frac{1}{\left( \text{Distance} \right)}\] Therefore, as distance is doubled, \[{{N}_{E}}\] decreases by (1/4) times.


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