Question

A conducting sphere with a radius of R = 9.3 mm has a uniform and constant surface charge density of teta= 10 nC / m2. What will be the magnitude of the electric field produced by that sphere at a distance from the center of the sphere der = 23.5 cm?

Answer 1

Surface area of sphere=4(r^2), where r is radius of the sphere.

Also, charge=(surface charge denisty)*area = *[4(r^2)], where is surface charge density.

Here,r=9.3 mm = 9.3*10^-3 m, =10 nC/m2 = 10^-8 C/m2

So, charge=10^-8*[4*(9.3*10^-3)^2] C = 1.086865394*10^-11 C

Electric field = kq/d^2, where k is a constant(=9*10^9 N-m2/C2), q is charge, d is distance between the charge and the point where electric field is to be calculated.

Here, q=1.086865394*10^-11 C, d=23.5 cm = 0.235 m.

So, electric field = (9*10^9)*(1.086865394*10^-11 ) / (0.235^2) = 1.77 N/C.