2. Sample Papers
  3. NEET

NEET Sample Paper NEET Sample Test Paper-54

  • question_answer
    In semiconductor the concentrations of electrons and holes are \[8\,\,\times \,\,{{10}^{18}}/{{m}^{3}}\] and \[5\,\,\times \,\,{{10}^{18}}/{{m}^{3}}\] respectively. If the mobilities of electrons and holes are \[2.3\,{{m}^{2}}/{{V}^{-2}}\] and 0.01 \[{{m}^{2}}/V-s\] respectively, then semiconductor is:

    A) n-type and its resistivity is \[0.34\,\Omega -m\]

    B) p-type and its resistivity is \[0.034\,\Omega -m\]

    C) n-type and its resistivity is \[0.034\,\Omega -m\]

    D) p-type and its resistivity is \[3.4\,\,\Omega -m\]

    Correct Answer: A

    Solution :

    \[{{n}_{e}}>>>{{n}_{h}}\] \[\therefore \] N type semiconductor \[\rho =\frac{1}{e[{{\mu }_{h}}{{n}_{h}}+{{\mu }_{e}}{{n}_{e}}]}\] \[=\,\,\frac{1}{1.6\times {{10}^{-19}}\left[ 2.3\times 8\times {{10}^{18}}+0.01\times 5\times {{10}^{18}} \right]}\] \[=\,\,\frac{1}{0.16\left[ 18.4+0.05 \right]}\,\,=\,\,\frac{1}{0.16\times 18.45}\] \[=\,\,\frac{1}{520}\,\,=\,\,0.34\,\Omega -m\]


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