The component of a vector r along X-axis will have maximum value if
(a) r is along positive Y-axis
(b) r is along positive X-axis
(c) r makes an angle of 45° with the X-axis
(d) r is along negative Y-axis
The answer is the option (b) r is along positive X-axis
Explanation: if a vector B forms an angle along the x-axis. Then its components along the x-axis can be written as B Cos θ.
The maximum value of , which is when .
Hence, for the vector r, the maximum value will be when it is along the positive x-axis.