A solid plastic sphere of radius R1 = 8.00 cm is concentric with an aluminum sph

Question

A solid plastic sphere of radius R1 = 8.00 cm is concentric with an aluminum spherical shell with inner radius R2 = 14.0 cm and outer radius R3 = 17.0 cm (see figure below). Electric field measurements are made at two points: At a radial distance of 34.0 cm from the center, the electric field has magnitude 9.00 x 103 N/C and is directed radially outward, and at a radial distance of 12.0 cm from the center, the electric field has magnitude 2.00 x 104 N/C and is directed radially inward. What are the net charges on the following? Plastic Aluminum (a) the plastic sphere (b) the aluminum spherical shell (c) What are the charges on the inner and outer surfaces of the aluminum spherical shell? Qinner Qouter

Explanation / Answer

Solution-

let the charge on plastic sphere be q

the charge on aluminum spherical shell be q1.

We know q1 will be totally on the outer surface of the aluminum spherical shell.

ar r=34 cm

E=k*(q+q1)/(0.34)^2= 9.00 10^3 (1)

at r=12 cm

E=kq/(0.12)^2= 2.00 10^4 (2) (It radially inward means q is negative)

=2.00*10^4*0.12^2/ 9*10^9

solving equation (2) q= -3.2*10^(-8) C

putting the value of q in (1) we get

q1=1.476*10^(-7) C

(a)charge on plastic =q=-3.2*10^(-8) C

(b) charge on aluminium shell=q1=1.476*10^(-7) C

(c) charge on inner surface=3.92*10^(-8)

on outer surface=1.0404*10^(-7) C

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

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