Dipole in a Uniform External Field

Assertion (A):  An electric dipole is placed in a uniform electric field. Its equilibrium will be stable when the dipole is set along the direction of the electric field.

Reason (R): In stable equilibrium energy of dipole should be the least possible.

What are the conditions for stable and unstable equilibrium for torque of an electric dipole placed in uniform electric field?

When electric dipole is kept in uniform electric field such that torque is zero and potential energy is maximum then equilibrium is

A dipole in stable equilibrium, when Electric filed and dipole moment are perpendicular to each other i.e. the angle between them is _____ degrees and torque will be maximum.

A dipole is said to be in stable equilibrium when angle between electric field and dipole moment is:​

The stable equilibrium the torque should be zero and the potential energy of the dipole should be minimum.

An electric dipole of length $1 \mathrm{cm}$ is placed with the axis making an angle of $30°$ to an electric field of strength ${10}^4 \mathrm{N} {\mathrm{C}}^{-1}$. If it experiences a torque of $10\sqrt{3} \mathrm{N} \mathrm{m}$, the potential energy (in joule) of the dipole is $-x \mathrm{J}$. Find the value of $x$.

If an electric dipole is placed in a uniform electric field, it experiences:

An electric dipole is placed in a uniform electric field. Assuming the angle between the electric field and dipole axis is $45°$, the dipole will experience

A dipole is said to be in unstable equilibrium when angle between dipole moment and electric field is

Assertion: Net electric force on electric dipole is zero in a uniform electric field.

Reason: Value of electric field at axis due to electric dipole is double of equatorial axis of it.

An electric dipole is placed at an angle of ${30}^o$ with an electric field of intensity $2\times {10}^5\mathrm{ }\mathrm{N }{\mathrm{C}}^{-1}.$ It experiences a torque equal to $4 \mathrm{N }\mathrm{m}$. Calculate the charge on the dipole if the dipole length is $2 \mathrm{c}\mathrm{m}$.

Two point masses, $m$ each carrying charges $-q$ and $+q$ are attached to the ends of a massless rigid non-conducting wire of length $L$. When this arrangement is placed in a uniform electric field, then it deflects through an angle $\theta$. The minimum time needed by the rod to align itself along the field is

Torque acting on an electric dipole in a uniform electric field is maximum when angle between $\overrightarrow{p}$ and $\overrightarrow{E}$ is ......... .

An electric dipole, consisting of two opposite charges of $2 \times {10}^{-6}C$ each separated by a distance 3 cm is placed in an electric field of $2 \times {10}^{5}N/C$ . Torque acting on the dipole is

An electric dipole is kept in a uniform electric field. It experiences

An electric dipole made up of a positive and negative charge, each of $1 \mathrm{\mu C}$ and placed at a distance $2 \mathrm{cm}$ apart. If the dipole is placed in an electric field of ${10}^5 \mathrm{N} {\mathrm{C}}^{-1}$, then calculate the maximum torque which the field can exert on the dipole if it is turned from a position $\theta =0^o to \theta ={180}^o$

The torque acting on dipole and potential energy are, respectively -

 

Two charges of $-4 \mathrm{\mu }\mathrm{C}$ and $+4 \mathrm{\mu }\mathrm{C}$ are placed at points $\mathrm{A}\left(1,\mathrm{ }0,\mathrm{ }4\right)$ and $\mathrm{B}\left(2,\mathrm{ }-1,\mathrm{ }5\right)$ located in an electric field $\overrightarrow{\mathrm{E}}=0.20\mathrm{ }\widehat{\mathrm{i}}\mathrm{ }\mathrm{V} {\mathrm{cm}}^{-1}$. The torque acting on the dipole is -

The electric dipole is situated in an electric field as shown in figure. Both the dipole and the electric field are in the plane of the paper. The dipole is rotated about an axis perpendicular to the plane of the paper and passing through a point $\mathrm{C}$ . The direction of rotation is anti-clockwise. If the angle of rotation $\mathrm{\theta }$ is measured with reference to a line which is perpendicular to the electric field then the variation of $𝜏$ with $\mathrm{\theta }$ is best represented by curve -