Question

Electric field produced by an electron at a point is $E$. What will be electric field produced by $Li^{+++}$ at the same point if it is placed at position of electron ?

• A. $E$
• B. $\frac{E}{2}$
• C. $3E$
• D. $\frac{E}{3}$

Answer 1

Answer: (C)

The magnitude of electric field produced, by electron at a point which at a distance $r$ from the electron is
$E=\frac{e}{4\pi\varepsilon_{0} r^{2}} \ldots\left(i\right)$
When the electron is replaced by the $Li^{+++}$ the electric field produced at the same point is
$E'=\frac{3e}{4\pi\varepsilon_{0} r^{2}}=3E$ (Using $\left(i\right))$