JEE Main & Advanced Sample Paper JEE Main - Mock Test - 27

  • question_answer
    In a single slit diffraction pattern, the distance between the first minimum on the left and the first minimum on the right is 5 mm. The screen on which the diffraction pattern is displayed is at a distance of 80 cm from the slit. The wavelength is \[\text{6000}\overset{\text{o}}{\mathop{\text{A}}}\,\]. The slit width (in mm) is about

    A) 0.576   

    B) 0.348

    C) 0.192

    D) 0.096

    Correct Answer: C

    Solution :

    [c] : Distance between the first minimum on the left and the first minimum on the right is also the width of central maximum. Width of central maximum,\[W=\frac{2\lambda D}{a}\]where, X = Wavelength of light a = Width of the slit D = Distance of the screen from the slit \[\therefore \]\[a=\frac{2\lambda D}{W}\] Here, \[\lambda =6000\overset{\text{o}}{\mathop{\text{A}}}\,=6000\times {{10}^{-10}}m,\] \[D=80cm=80\times {{10}^{-}}^{2}m\] \[V=5mm=5\times {{10}^{-3}}m\] \[\therefore \]\[a=\frac{2\times 6000\times {{10}^{-10}}m\times 80\times {{10}^{-2}}m}{5\times {{10}^{-3}}m}\] \[=19.2\times {{10}^{-5}}m=0.192\times {{10}^{-3}}m=0.192mm\]


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