Electrostatics Question 5

Question 5 - 25 January - Shift 2

A point charge of $10 \mu C$ is placed at the origin. At what location on the $X$-axis should a point charge of $40 \mu C$ be placed so that the net electric field is zero at $x=2 cm$ on the $X$-axis ?

(1) $x=6 cm$

(2) $x=4 cm$

(3) $x=8 cm$

(4) $x=-4 cm$

Show Answer

Answer: (1)

Solution:

Formula: Coulomb Force

$2 cm(x_0-2) cm$

$E_P=\frac{K \times 10}{2^{2}}-\frac{K \times 40}{(x_0-2)^{2}}=0$

$\frac{1}{2}=\frac{2}{x_0-2}$

$x_0-2=4$

$x_0=6 cm$