Page 14 - Electrostatics 11

Grade 11 © GC Shiba
1
= ∫ − 2
0
2 4

1 1
= − ∫
4 0 2 2

1
= − ∫ −2
4 0 2

−2+1 1
= − [ ]
4 0 −2 + 1 2

1 1
= − [ − ]
4 0 1 2

− 1
2
= − [ ]
4 0 . 2
1
By definition, this work done is electric potential difference (V).
− 1
2
∴ = − [ ]
4 0 . 2
1

This is the required expression for electric potential difference between
points A and B.

Electric potential at a point due to number of charges:

Electric potential at a point due to the number of charges is the algebraic sum
of electric potentials due to individual charges.

P

rn
r1

r3 Qn
r2

Q1
Q3

Q2

V = V1 + V2+ V3+ ... ... ... + Vn

14 Electrostatics