A metal sphere with radius r a = 1.20 cm is supported on an insulating stand at
ID: 776972 • Letter: A
Question
A metal sphere with radius ra = 1.20 cm is supported on an insulating stand at the center of a hollow, metal, spherical shell with radius rb = 9.10 cm . Charge +q is put on the inner sphere and charge q on the outer spherical shell. The magnitude of q is chosen to make the potential difference between the spheres 400 V , with the inner sphere at higher potential.
Part A:Calculate q
Part B:
Are the electric field lines and equipotential surfaces mutually perpendicular?
Part C:
Are the equipotential surfaces closer together when the magnitude of E is largest?
Yes NoExplanation / Answer
a) V = k q / ra - k q / rb
400 = 8.99 * 109 * q [1 / 0.012 - 1/0.091]
q = [400 / 8.99 * 109] / [1 / 0.012 - 1/0.091]
q = 6.14 * 10-10 C
b) YES, electric field lines and equipotential surfaces are mutually perpendicular
c) Equipotential surfaces closer together when the magnitude of E is largest