Answer
Horizontal plane
Work Step by Step
The conversion of rectangular coordinates to spherical coordinates is given as:
$x=\rho \sin \phi \cos \theta; y=\rho \sin \phi \sin \theta;z=\rho \cos \phi$
Here, $\rho=\sqrt {x^2+y^2+z^2}$; $\phi =\cos^{-1} [\dfrac{z}{\rho}]; \theta=\cos^{-1}[\dfrac{x}{\rho \sin \phi}]$
Here, we have $\rho \cos \phi=1$
and $\phi =\cos^{-1} [\dfrac{z}{\rho}]$
This gives: $z=1$
Hence, the value of $z=1$ shows a horizontal plane parallel to xy plane having $z$-intercept at $1$.
