Question

An electric dipole of moment placed in uniform electric field has
minimum potential energy. The work done by external agent to rotate
this dipole very slowly upto which it has maximum potential energy
1.-PE
2.2PE
3.PE/2
4.zero
pls answer fast​

Answer 1

Answer:

C

π

Potential Energy=−PEcosθ

when

θ=0

Potential Energy=−PE

When

θ=180

Potential Energy=+PE

So, Maximum Potential Energy=+PE at angle θ=π

Answer 2

Answer:

The work done by external agent = +2PE

Explanation:

Potential Energy of an electric dipole = - PEcosθ          

Minimum Potential Energy happens at θ=0°

As cos 0° = 1,

∴ Minimum Potential Energy of the electric dipole = -PE

The dipole is rotated using an external agent,

So at θ= 180 °,

Potential Energy of the electric dipole at θ= 180 °= -PE cos 180 °

==PE$\times$-1

=+PE

∴The maximum Potential Energy of the electric dipole= +PE

Work done to attain maximum Potential Energy of the electric dipole =

Maximum Potential Energy - Minimum Potential Energy

=+PE- (-PE)

= +2PE

∵ The work done by external agent to rotate this dipole to maximum potential energy =+2PE