Question

25)). the magnitude of electric potential on equatorial line due to an electric dipole is E1 and the magnitude of electric potential on axial line is E2 the value of E1+E2 is equal to:

a) 2E2
b) E2
c) E1
d) 2E1

Answer 1

Correct option is

C

E

1

=−2E

2

On equatorial line the electric field is given by:

E

2

=

4πε

o

1

r

3

2p

On axial line the field is:

E

1

=

4πε

o

1

r

3

p

But since the directions are opposite:

E

1

=−2E

2

Answer 2

Answer:

The value of E₁+E₂ is equal to E₂ i.e.option(b).

Explanation:

The electric potential on the equatorial line due to an electric dipole is,

$E_1=0$        (1)

Whereas electric potential on the axial  line due to an electric dipole is,

$E_2=\frac{Kp}{r^2-a^2}$      (2)

Where,

E₂=electric potential on the axial  line of the dipole

K=coulombs constant

p=dipole moment

r=distance of the point from the dipole

a=half the length of the dipole

And from the question we have,

$E=E_1+E_2$      (3)

By using equations (1) and  (2) in equation (3) we get;

$E=0+\frac{Kp}{r^2-a^2}$

∴$E=E_2$

Hence, the value of E₁+E₂ is equal to E₂ i.e.option(b).