Answer
Cylinder with radius $1$
Work Step by Step
Given: $r=2 \sin \theta$
We know that in the cylindrical co-ordinates $r^2=x^2+y^2 \implies r=\sqrt{x^2+y^2}$ and $y=r \sin \theta$
Thus, we have
$x^2+y^2=2y$
This can be written as:
$x^2+y^2-2y=0 \implies x^2+y^2-2y+1=1 $
or, $x^2+(y-1)^2=1^2$
Thus, it represents an equation of a cylinder with radius $1$ .