Along cylindrical shell with a radius of 1cm has a charge uniformly distributed on its surface. if the magnitude of the electric field at a point 8cm radially outward from the axis of the shell is 85 n/c, how much charge is distributed on a 2m length of the charged cylindrical surface?

756.25 *10^-12 C

Explanation: In order to explain this problem we have to consider that the electric field for large charged cylinder is given by:

E=λ/(2*π*εo*r) where λ is the charge per length. r is the distance to the cylinder centre.

then we have:

λ= E * 2*π*εo*r= 85*2*π*8.85*10^-12*0.08=378.12 C/m

for 2 meter long we have a total charge of:

Q=λ*L=378.12 C/m*2m=756.25 *10^-12 C

firearm identification is the process of analyzing the bullets and cartridge cases left at a crime scene to determine if they came from a particular firearm. marks on the bullets and cartridges may be common to every firearm of that type. these are called class characteristics.