In the figure a sphere, of radius a = 15.6 cm and charge q = 6.00×10 -6 C unifor

Question

In the figure a sphere, of radius a = 15.6 cm and charge q = 6.00×10-6C uniformly distributed throughout its volume, is concentric with a spherical conducting shell of inner radius b = 26.5 cm and outer radius c = 28.5 cm . This shell has a net charge of -q.

a) Find expressions for the electric field, as a function of the radius r, within the sphere and the shell (r < a). Evaluate for r = 7.8 cm.

b) Find expressions for the electric field, as a function of the radius r, between the sphere and the shell (a < r < b). Evaluate for r=21.1 cm.

c) Find expressions for the electric field, as a function of the radius r, inside the shell (b < r < c). Evaluate for r = 27.5 cm.

Explanation / Answer

a)

Qnet = ((4/3)*r^3/((4/3)a^3))q = q (r/a)^3

E = Qnet/A = q (r/a)^3/(4r^2) = q r/(4a^3)

E(r=7.8cm) = 6*10^-6*0.078*9*10^9/(0.156^3) = 1.11*10^6 N/C

b)

E = q/(4r^2)

E(21.1 cm) = 6*10^-6*9*10^9/(0.211^2) = 1.21*10^6 N/C

c)

E = 0 (everywhere)

E(27.5 cm) = 0.

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.