# Two point charges of 5C and 20C are separated by a distance of 6m . Find the point on the line joining them at which electric field intessity is zero .

$(a)\;2m \;from\; 5C \qquad(b)\;2m\;from\;20C\qquad(c)\;3m\;from\;5C\qquad(d)\;1m\;from\;5C$

Answer : $\;2m\;from\;5C$
Explanation : For E to be zero at a distance x from 5C
$\large\frac{k\;5}{x^2}=\large\frac{k\;20}{(6-x)^2}$
$(6-x)^2=4x^2$
$6-x=2x$
$x=2m.$
edited Mar 25, 2014 by yamini.v