JEE Main & Advanced Physics Wave Optics / तरंग प्रकाशिकी Question Bank Mock Test - Wave Optics

  • question_answer
    The wave front of a light beam is given by the equation \[x+2y+3x=c\](where c is arbitrary constant), then the angle made by the direction of light with the y-axis is

    A) \[{{\cos }^{-1}}\frac{1}{\sqrt{14}}\]    

    B) \[{{\sin }^{-1}}\frac{2}{\sqrt{14}}\]

    C) \[{{\cos }^{-1}}\frac{2}{\sqrt{14}}\]    

    D) \[{{\sin }^{-1}}\frac{3}{\sqrt{14}}\]

    Correct Answer: C

    Solution :

    [c] Here, direction of light is given by normal vector \[\vec{n}=\hat{i}+2\hat{j}+3\hat{k}\] \[\therefore \]Angle made by the \[\vec{n}\]with y-axis is given by \[\cos \beta =\frac{2}{\sqrt{{{1}^{2}}+{{2}^{2}}+{{3}^{2}}}}=\frac{2}{\sqrt{14}}\]


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