19201/BEE3113
QUESTION 2
(a)
Determine the total charge:
(i) on the line $0 \le y \le 6$ m positioned at $x = 2$, if line charge density, $\rho_l = 12y^2x$ mC/m
on the cylinder $\rho = 4$, $0 \le z \le 4$ m if the surface charge density, $\rho_s = \rho z^2$ nC/m$^2$
(ii)
[5 Marks]
[CO1, PO1, C3]
(b)
Polluted smoke particles exited from industrial chimneys can be reduced by using electrostatic
force to capture the polluted charged particles. Figure 2 shows one type of positive circular line
charge used in chimneys to attract the smoke particles.
(i) Show that the electric field intensity, E at (0,0,h) in cylindrical coordinates due to
circular line of charge with $\rho = a$ at $z = 0$ is
$E = \frac{(ah)^2}{2(a^2 + h^2)}^\frac{3}{2} a_$\n[5 Marks]
[CO2, PO2, C4]
(ii) Investigate the pattern of electric field, E at (0,0,4) m if the radius a of the chimney is
varied from 1 m to 18 m by plotting E versus a.
[5 Marks]
[CO3, PO4, C4]
