Two point charges, \(+2\,\mu\text{C}\) and \(-2\,\mu\text{C}\), are fixed respectively at points \(A\) and \(B\), separated by \(4\,\text{m}\) in air. A point \(P\) is located such that it is \(3\,\text{m}\) from \(+2\,\mu\text{C}\) and \(5\,\text{m}\) from \(-2\,\mu\text{C}\). What is the electric potential at point \(P\)?
\[
k=9\times10^9\,\text{N m}^2\text{C}^{-2}
\]
Show Hint
Electric potential is a scalar quantity, so potentials are added algebraically:
\[
V=\sum \frac{kq_i}{r_i}.
\]
Positive charges contribute positive potential and negative charges contribute negative potential.
Concept:
The electric potential at a point due to a system of point charges is the algebraic sum of the potentials due to individual charges.
\[
V=\sum \frac{kq}{r}.
\]
Step 1: Calculate the potential due to the charge \(+2\,\mu\text{C}\).
\[
V_1
=
\frac{k(2\times10^{-6})}{3}.
\]
\[
V_1
=
\frac{9\times10^9\times2\times10^{-6}}{3}.
\]
\[
V_1
=
6\times10^3\,\text{V}.
\]
Step 2: Calculate the potential due to the charge \(-2\,\mu\text{C}\).
\[
V_2
=
\frac{k(-2\times10^{-6})}{5}.
\]
\[
V_2
=
-\frac{9\times10^9\times2\times10^{-6}}{5}.
\]
\[
V_2
=
-3.6\times10^3\,\text{V}.
\]
Step 3: Find the resultant potential at point \(P\).
\[
V
=
V_1+V_2.
\]
\[
V
=
6\times10^3-3.6\times10^3.
\]
\[
V
=
2.4\times10^3\,\text{V}.
\]
Step 4: Write the final answer.
\[
\boxed{V=2.4\times10^3\,\text{V}}
\]
\[
\boxed{\text{Answer = (B)}}
\]