Assuming that an infinitely long line charge of 50(pC/m) parallel to the y-axis at x=2(m) and z=1(m), determine the electric intensity at the point (-1, 5, -3).
The answer given : -0.18(ax0.6 + az0.8)(V/m)
Electric field intensity due to an infinite straight line charge of uniform density :
E= ar("rho" / (2"pi""epsolon 0"r) ( V/m)
The Attempt at a Solution
I let point P = -ax + ay5 - az3
Point on line perpendicular to point P, Q = ax2 + az
Vector Q to P = -ax3 + ay5 - az4
I found out that if i ignore or make coefficient of ay to zero and apply the above formula i'll get the answer..
but i do not understand why..please help