JEE TYPE

The slanting surface of the cone provides the normal reaction.
The normal reaction has 2 components.
The vertical component balances the weight of the particle
The horizontal component balances the centripetal force due to the movement of the particle in horizontal path.
Hence .....

Nsin∞= mv²/r
Ncos∞= mg .... where m is the mass of the particle.
tan∞=v²/rg
r=v²/gtan∞

Let us cosider the ht. at which the particle is present is h

h=rtan∞
h=v²/gtan∞ * tan∞
h=v²/g
PE=mgh=mg*v²/g
PE=mv²
KE=1/2*mv²
Therefore ....... PE=2*KE. [Relation]

Hey Vardaan ... is my ans correct ... ???

Nishant sir ... would u please check if my logic is correct ... ???