For an infinitely long metal cylinder, the radius is 3 mm, K=6.28 annd charge density`=4muC//m^(2)`. What is the electric intensity (E) at a distance of 1.5 m from the axis? `[(1)/(4piepsi_(0))=9xx10^(9)]`

Options

A. 144 N/C
B. 160 N/C
C. 288 N/C
D. 72 N/C

Answer

A

Explanation

Surface charge density `sigma=4xx10^(-6)C//m^(2)`
The electric intensity at a distance r from the axis is given by
`E=(sigmaR)/(eepsi_(0)K)=(1)/(4piepsi_(0))xx(4pisigmaR)/(Kr)`
`therefore E=(9xx10^(9)xx4xx3.14xx4xx10^(-6)xx3xx10^(-3))/(6.28xx1.5)`
`therefore E=144N//C`