The wavefront 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

Options

A. `cos^(1) .(1)/(sqrt(14))`
B. `sin^(1).(2)/(sqrt(14))`
C. `cos^(1).(2)/(sqrt(14))`
D. `sin^(1).(3)/(sqrt(14))`

Answer

c

Explanation

Here, direction of light is given by normal vector
`vec n = hat I + 2 hat j + 3 hat k`
`:.` Angle made by the `vec n` with y-axis is given by `cos beta =`
`(2)/(sqrt(1^(2) + 2^(2) + 3^(2))) = (2)/(sqrt 14)`