NEET AIPMT SOLVED PAPER MAINS 2011

  • question_answer
    The threshold frequency for a photo-sensitive metal is 3.3 x1014 Hz. If light of frequency 8.2 x 1014 Hz is incident on this metal, the cut-off voltage for the photo-electric emission is nearly          

    A)  2 V                        

    B)  3 V                        

    C)  5 V                        

    D)  1 V

    Correct Answer: A

    Solution :

    \[{{V}_{0}}=\frac{E-V}{e}\] \[=\frac{h(v-{{v}_{0}})}{e}\] \[=\frac{6.62\times {{10}^{-34}}(8.2\times {{10}^{14}})(8.2\times {{10}^{14}})-3.3\times {{10}^{14}})}{1.6\times {{10}^{-19}}}\]\[=\frac{6.62\times {{10}^{-34}}}{1.6}\times 4.9\times {{10}^{33}}\] \[=\frac{6.62\times 4.9\times {{10}^{-1}}}{1.6}\] \[{{V}_{0}}=2\,volt\]


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