Question

Two charges of +2 nC & -3 nC are at the two ends of a meter scale. Find the electric potential at the midpoint

Answer 1

Answer :

Two charges of +2 nC and -3 nC are placed at the two ends of a meter scale.

We have to find the electric potential at the midpoint $.$

$\star$ Electrical potential is a scalar quantity having only magnitude therefore we can directly add potential due to each charge in order to get net potential at midpoint.

• The electric potential near an isolated positive charge is positive because work has to be done by an external agent to push a positive charge in, from infinity.
• The electric potential near an isolated negative charge is negative because the positive test charge is attracted by the negative charge.

Since both charges are placed at equal distance from midpoint, net potential at midpoint will be zero because positive potential of positive charge and negative potential of negative charge will cancel out each other.

∴ Net electric potential at the midpoint = 0