First i want to thank all the Members who are sharing us thier knowledge and science . Second i will try my best to help others and share information to all . Third please excuse me because of my english language i am weak at it. I have 9 questions for my homework which is due to this Thursday. Its actually 21 questions but i solved the others except these questions so i hope i get hints or clues for my questions. I will be very happy if at least one question is been answered because i will feel that i've been accepted to be a member of this forums. Forgive me because i have asked too much questions in my first post. Here are the Questions , Question #1 Consider the uniformly charged sphere with radius R = 4.65461 m, Q = 6.66731 μC is the total charge inside the sphere. a) Find the total flux passing through the Gaussian surface (a spherical shell) with ra- dius 2.08762 m. b) Find the electric field at radius r = 2.08762 m. c) Find the value of the electrostatic potential at the same radius r = 2.08762 m. Relevant Formula : V=kq/r I have answered part a & b correctly except part c So guys help me out in this part & thx in Advance. Question #2 A charge of 9.054 nC is uniformly distributed along the x-axis from −5 m to 5 m. What is the electric potential (relative to zero at infinity) of the point at 6 m on the x-axis? Question # 3 Given : ke = 8.98755 × 10^9 Nm2/C2 . A uniformly charged insulating rod of length 21.9 cm is bent into the shape of a semicircle. If the rod has a total charge of −8.21 μC. a) Find the horizontal component of the electric field at O, the center of the semicircle. Hint: Define right as positive. b) Determine the value of the electric potential V at the center of the semicircle. Question # 4 Consider a solid conducting sphere with a radius a and charge Q1 on it. There is a conducting spherical shell concentric to the sphere. The shell has an inner radius b (with b > a) and outer radius c and a net charge Q2 on the shell. Denote the charge on the inner surface of the shell by Q′2 and that on the outer surface of the shell by Q′′2 . http://www.up-00.com/s1files/a5c29970.jpg [Broken] Assume: The potential at r = 1 is zero. Find the potential VP at point P, which is the midpoint between a and b. Question # 5 The electric potential in a certain region is V = a x2 + b x + c, where a = 19 V/m2, b = −19 V/m, and c = 55 V. Determine the position where the electric field is zero. Question # 6 A uniform electric field is in the negative x direction. Points a and b are on the x-axis, a at x = 3 m and b at x = 11 m. If the magnitude of Vb − Va is 2.06 × 10^5 V, what is the electric field? Question # 7 A particle of mass 3 × 10−4 kg and charge 3 μC moves downward from point A to point B a distance of 5 m in the earth’s gravita- tional field. The kinetic energy of the particle decreases by 3.9 mJ during this movement. The acceleration of gravity is 9.8 m/s2 . What is the potential difference VB − VA? Question # 8 Calculate the surface charge density for a solid spherical conductor of radius 0.371 m if the potential is 0.703 m from the center of the sphere is 2.90 kV. Question # 9 Points A (2 m, 6 m) and B (9 m, 14 m) are in a region where the electric field is uniform and given by ~E = Exˆı + Ey ˆj, where Ex = 8 N/C and Ey = 3 N/C. What is the potential difference VA − VB? Please Friends Any help In any question above will help me very much & i will be gratefull to you.