An infinitely long positively charged cylindrical shell of radius a has a unifor
ID: 1588385 • Letter: A
Question
An infinitely long positively charged cylindrical shell of radius a has a uniform linear charge density a. An infinitely long cylindrical shell of radius b>a is concentric with the first and has a uniform linear charge density b.
Choose the correct expression for E(r)
A)
B) E (r<a)=(2k(ba))/r radially outward from the center of the cylinder
E (a<r<b)=(2ka)/r radially outward from the center of the cylinder
E (r>b)=(2k(a+b))/r radially outward from the center of the cylinder
C)
E (r<a)=(2k(ba))/r toward the center of the cylinder
E (a<r<b)=(2ka)/r radially outward from the center of the cylinder
E (r>b)=(2k(a+b))/r toward the center of the cylinder
D)
E (r<a)=0
E (a<r<b)=(2ka)/r radially outward from the center of the cylinder
E (r>b)=(2k(a+b))/r radially outward from the center of the cylinder
E (a<r<b)=(2ka)/r toward the center of the cylinder
E (r>b)=(2k(a+b))/r toward the center of the cylinder
Explanation / Answer
electric due to long cylindrical shell at a distance r E = 2*k*/(r)
E(r<a) = 0
E(a<r<b) = 2*k*a/r radially outward from the center of the cylinder
E(r>b) = 2*k*a/r + (2*k*b)/r = ( a+ b) / r radially outward from the center of the cylinder
option (D)