A charge situated at a certain distance along the axis of an electric dipole experience a force F. If the distance of the charge from the dipole is doubled, the force acting on it will become

Question

A charge situated at a certain distance along the axis of an electric dipole experience a force F. If the distance of the charge from the dipole is doubled, the force acting on it will become (A) 2F (B)  ( F/ 2) (C)  ( F/ 4) (D)  ( F/ 8)

Tardigrade Admin · Accepted Answer

The electric field at a point distance r from electric dipole is
E =

\frac{1}{4 π ε _{0}} . \frac{2 p}{r ^{3}}

..( axial line)
where pis dipole moment and ris the distance of charge from centre of dipole.
or

E \propto \frac{1}{r ^{3}}

Force on charge is
F = QE
or

F \propto \frac{1}{r ^{3}}

∴ \frac{F _{2}}{F} = (\frac{r}{2 r})^{3} = \frac{1}{8}

or

F_{2} = \frac{F}{8}

Q. A charge situated at a certain distance along the axis of an electric dipole experience a force $F$ . If the distance of the charge from the dipole is doubled, the force acting on it will become

$2 F$

$\frac{F}{2}$

$\frac{F}{4}$

$\frac{F}{8}$

Q. A charge situated at a certain distance along the axis of an electric dipole experience a force F. If the distance of the charge from the dipole is doubled, the force acting on it will become

2F

2F​

4F​

8F​

The electric field at a point distance r from electric dipole is E = 4πε0​1​.r32p​ ..( axial line) where pis dipole moment and ris the distance of charge from centre of dipole. or E∝r31​ Force on charge is F = QE or F∝r31​ ∴FF2​​=(2rr​)3=81​ or F2​=8F​

Q. A charge situated at a certain distance along the axis of an electric dipole experience a force $F$ . If the distance of the charge from the dipole is doubled, the force acting on it will become

$2 F$

$\frac{F}{2}$

$\frac{F}{4}$

$\frac{F}{8}$