Torque on a Dipole in a Uniform Electric Field

New topics introduced every day help ensure that science never ceases to be a mystery. The charge is everywhere throughout our day-to-day lives, and it causes various natural events to occur. There are also positive and negative forms of charge. Charge exhibits multiple properties when exposed to stimulating fields. This article explains an effect known as torque on a dipole in a uniform electric field.

What is torque?

The torque defined here is the tendency of a force to cause a body to rotate about its axis in a specific direction. It is well known that the charge exists in the surrounding universe, and along with its existence, it is responsible for a wide array of natural phenomena.

Electric dipole

The term dipole describes two charges with the same magnitude but in the opposite sign. There is a negative to a positive charge direction in this quantity. For a simple dipole made of just two charges, the electric dipole equals the strength times the separation between the charges.

The dipole limit refers to the distance between the generating charges that should converge to zero when calculating dipole moments.

Moments on a dipole in a uniform electric field measure the distance between positive and negative charges. The strength or weakness of the system is said to determine the system’s polarity. An electric dipole’s moment is measured in coulomb-metres (C m).

Based on the distance and magnitude of the charges, we can determine the moment of the dipole. Moment vectors illustrate how torque on a dipole in a uniform electric field goes from unstable to stable equilibrium.

Energy and torque

Place a dipole object in the presence of an electric field and experience torque T. As a result, the dipole will be aligned with the electric field. Compared to a dipole making an angle with an electric field, a parallel dipole has lower potential energy. The dipole vector and field vector lies on the same plane, and the torque takes the right-hand rule direction inside that plane. The direction of an accelerating non-uniform field gradient can cause a Torque on a dipole in a uniform electric field, and force can be exerted in the direction of the dipole moment. A parallel force will always result from the dipole moment depending on whether the dipole is parallel or antiparallel.

An electric dipole’s torque

When placed in an external field, the torque on a dipole in a uniform electric field can be calculated by considering a dipole that is placed in a uniform external area called E. qE will be applied in the upward direction. It will be applied in the downward direction to the positive charge. The dipole is in translational equilibrium since the net force is zero. So, where do we find the rotational equilibrium? The dipole may remain fixed but rotate at an angular speed in this case. Electrostatic forces (qE) are characterised as clockwise torques, and this fact has been empirically demonstrated. Consequently, when a uniform electric field surrounds a dipole, it will rotate. You should never forget that torque produces two forces. Additionally, its magnitude results from force multiplied by the arm. An arm identifies the distance between the point where rotation occurs during dipole rotation and the point where the force is applied.

Torque on a dipole in a uniform electric field

An external electric field has already been shown to affect charges; a dipole will also be involved in one way. An external electric field causes a dipole to acquire a rotating effect. Torque on a dipole in a uniform electric field results from this rotating effect. The net torque can determine the overall velocity using the opposite charges present in a dipole.

Calculation of torque

If a dipole is introduced to a uniform external field, we can determine the torque experienced by the dipole. This force will affect positive charges in an upward direction with qE magnitude, whereas negative charges will be affected by qE magnitude downward forces.

In translational equilibrium, the net force is zero, so we can see that the dipole is resting. In rotational equilibrium, the net force is positive. A dipole, in this case, may remain in a stationary position while rotating with an angle of rotation.

The truth is that electrostatic forces (qE) produce torque when applied clockwise, as proven experimentally. In the uniform external electric field, the dipole does rotate, and torque always behaves as a couple. Furthermore, its magnitude equals the sum of its force and its arm.

Dipoles can be described in this way as having arms that divide the point at which force is applied from the point at which rotation occurs.

Conclusion

Dipoles are electric charges with opposite polarities separated by a distance, ‘d’. When an object rotates about an axis, the force that causes the rotation is torque. Given that the magnitudes of the forces are equal and separated by d, the torque on the dipole can be calculated by: 

Torque = Force x the distance between the forces.