If $z = \frac{3}{2 + \cos \theta + i \sin \theta}$,then the locus of $z$ is :-

If $|z|=1$ and $w=\frac{z-1}{z+1}$ (where $z \neq -1$),then $\operatorname{Re}(w)$ is

If $a$ is a complex number and $b$ is a real number,then the equation $\bar{a}+a+b=0$ represents $a$ as a locus of points in the complex plane,which is a:

The locus of $z$ satisfying $\left|\frac{z-i}{z-2i}\right|=2$ is a

If $z_1, z_2, z_3 \in \mathbb{C}$ are the vertices of an equilateral triangle,whose centroid is $z_0$,then $\sum_{k=1}^3 (z_k - z_0)^2$ is equal to

If ${Z_1} \ne 0$ and ${Z_2}$ are two complex numbers such that $\frac{{{Z_2}}}{{{Z_1}}}$ is a purely imaginary number,then $\left| {\frac{{2{Z_1} + 3{Z_2}}}{{2{Z_1} - 3{Z_2}}}} \right|$ is equal to