The electric potential immediately outside a charged conducting sphere is $210$ V$,$ and $10\mathrm{.}0$ cm above the surface of the sphere the potential is $130$ V$.$

$($a$)$ Determine the radius of the sphere.

$16\mathrm{.}25$ cm

$($b$)$ Determine the charge on the sphere.

$3\mathrm{.}79$ nC

The electric potential immediately outside another charged conducting sphere is $230$ V$,$ and $10\mathrm{.}0$ cm above the surface of the sphere the magnitude of the electric field is $360$ V$/$m$.$

$($c$)$ Determine all possible values for the radius of the sphere. $($Enter your answers from smallest to largest. If only one value exists, enter "NONE" in the second answer blank.$)$

r$1=50\mathrm{.}23$

Your response differs significantly from the correct answer. Rework your solution from the beginning and check each step carefully. cmr$2=0\mathrm{.}4606$

Your response differs significantly from the correct answer. Rework your solution from the beginning and check each step carefully. cm

$($d$)$ Determine the charge on the sphere for each value of r$.($If only one value exists, enter "NONE" in the second answer blank.$)$

q$1=($No Response$)$ nCq$2=($No Response$)$ nC