TWO point charges $+ 2 n c$ and $- 4 n c$ are $1 m$ apart in air. Find the positions along the line joining the two charges at which resultant potential is zero.

Open in App

Solution

Let the potential at point P is zero which is situated at a distance $x$ to the left of $1 n C$ charge as shown in the figure.
Potential due a charge $q$ is given by $V = \frac{k q}{r}$ where $k = \frac{1}{4 π ϵ_{o}}$
Thus potential at point P $V_{p} = \frac{k (1 n C)}{x} - \frac{k (4 n C)}{1 + x}$
But $V_{p} = 0$
$∴$ $\frac{k (1 n C)}{x} - \frac{k (4 n C)}{1 + x} = 0$
Or $\frac{1}{x} - \frac{4}{1 + x} = 0$
Or $\frac{1}{x} = \frac{4}{1 + x}$
Or $3 x = 1$
$⟹$ $x = 0.33 m$

Suggest Corrections

Similar questions

Q. Two point charges of

+ 16 μ C

and

- 9 μ C

are placed

8 c m

apart in air. Determine the position of the point at which the resultant field is zero.

Q. Two charges

5 \times 10^{- 8} C

and

- 3 \times 10^{- 8} C

are located

0.16 m

apart. At what point(s) on the line joining the two charges in the electric potential zero? Take the potential at infinity to be zero.

Two electric charges of $9 μ C$ and $- 3 μ C$ are placed $0.16 m$ apart in air. There will be a point P at which electric potential is $z e r o$ on the line joining the two charges and in between them. The distance of P from $9 μ C$ charge is:

Two charges 5 × 10⁻⁸ C and −3 × 10⁻⁸ C are located 16 cm apart. At what point(s) on the line joining the two charges is the electric potential zero? Take the potential at infinity to be zero.

Q. Two charges

3 \times 10^{- 8} C

and

- 2 \times 10^{- 8}

are located

15 c m

apart. At what point on the line joining the two charges is the electric potential is zero?

Join BYJU'S Learning Program

TWO point charges +2nc and −4nc are 1 m apart in air. Find the positions along the line joining the two charges at which resultant potential is zero.

TWO point charges $+ 2 n c$ and $- 4 n c$ are $1 m$ apart in air. Find the positions along the line joining the two charges at which resultant potential is zero.