help please show your clear solution

for better understanding and no cursive writing please

typewritten will do or handwritten also

7What is the electric potential relative to infinity at the center of a ring with diameter d and charge -Q uniformly distributed around it? Consider the cross sections of equipotential surfaces of the point charges q, and 92 as shown. What is the nature of the charges? P +4.01 +3.0V +2.0V A. 1911 192l, same signs D. 1911 = 192l, opposite signs Sharks can detect weak electric fields as low as 5 x 10-7N/C, produced by the muscular contractions in their prey. If a scientist wants to simulate these fields using a parallel metal plates connected to a 9-V battery across the plates, what should be the distance between these plates