Question

Two charges of +10C and -10C are placed at distance of 10cm the electric potential at a point M exactly in middle is
a) zero
b) 10V
c) 0.8V
d) -10V​

Answer 1

Given:

Two charges of +10C and -10C are placed at distance of 10cm.

To find:

Potential at midpoint joining the charges ?

Calculation:

The net potential will be :

$V = \dfrac{kq_{1}}{r_{1} } + \dfrac{kq_{2}}{r_{2} }$

• Since midpoint is being considered, r1 = r2.

$\implies V = \dfrac{k(10)}{r } + \dfrac{k( - 10)}{r }$

$\implies V = \dfrac{k(10)}{r } - \dfrac{k( 10)}{r }$

$\implies V = 0 \: volts$

So, net potential at midpoint is zero.