Question

The component of a vector `r` along X-axis will have maximum value if
A. e is along positive Y-axis
B. r is along postiveY-asis
C. x makes an angle of `45^(@)` with the X-axis
D. r is along nehnitive Y-axis

Answer 1

Correct Answer - B
(b) Let r makes asn angle `theta` with positive x-axis component of along X-axis
`r_(x)=|r|costheta`
`(r_(x))_("maximum")=|r|(costheta)_("miximum")`
`=|r|cos0^(@)=|r|`
`(because costhetais maximumof theta=0^(@)`