CDS 2019 PYQ with Answer — In spherical polar coordinates (ρ, θ, α), θ denotes the polar angle a…

2019 · Q82

In spherical polar coordinates (ρ, θ, α), θ denotes the polar angle around z-axis and α denotes the azimuthal angle raised from x-axis.

Then the y-component of |P→| is given by

General KnowledgePhysics

APsin θ.sin α
BPsin θ.cos α
CPcos α.sin α
DPcos θ.cos α

Explanation

In spherical polar coordinates, the position components are x = P sin(theta) cos(alpha), y = P sin(theta) sin(alpha) and z = P cos(theta), where theta is the polar angle from the z-axis and alpha the azimuthal angle from the x-axis. The y-component is therefore P sin(theta) sin(alpha). Hence option A is correct.