An electric dipole in an electric field that is external is subjected to a torque written as τ = pE sin θ where symbol θ is the angle which is between p and E. The torque tends to align the moment of the dipole p in the direction of E.
What is the effect of torque in an electric field?
Answer: Even though the two forces on the ends of the dipole cancel as free vectors, they act at different points. This means that they give rise to a torque on dipole. The turning effect of this torque is to reduce the angle q towards zero, and make the dipole moment vector become parallel to the field.
What is electric dipole establish the necessary formula for the torque acting on electric dipole in a uniform electric field?
Show that the torque on an electric dipole placed in a uniform electric field is →τ=→P×→E. … A pair of electric charges with an equal magnitude but opposite charges separated by a distance is known as an electric dipole.
What is the total charge force torque of dipole in uniform electric field?
The net force acting on a dipole placed in a uniform electric field is zero. The forces on the two charges constituting the dipole are equal and opposite. Hence, the net force is zero.
What is torque in magnetic field?
A magnetic field exerts a torque which tries to align the normal vector of a loop of current with the magnetic field. The size of the torque on a loop of current is torque = (# turns) * (current) * (loop area) * (mag field) * sin(theta) where theta is the angle between the magnetic field and the loop’s normal vector.
What is the formula for electric dipole moment?
The formula for electric dipole moment for a pair of equal & opposite charges is p = qd, the magnitude of the charges multiplied by the distance between the two.
What is torque P E?
Torque = Force × distance between forces
τ = (q E sinθ) d = q d E sinθ Since ‘qd’ is the magnitude of dipole moment (p), and the direction of dipole moment is from positive to negative charge; torque is the cross product of dipole moment and electric field.
What is the SI unit of torque?
Unit of torque: newton metre (N m)
The quantity torque (or moment of force) may be thought of as the cross product of force and distance and the SI unit for torque is Newton metre, N m (m2 kg s–2).
Is torque a scalar or vector quantity?
Torque is a vector quantity. The direction of the torque vector depends on the direction of the force on the axis.
What is torque in physics class 12?
Torque is the measure of the force that can cause an object to rotate about an axis. … Hence, torque can be defined as the rotational equivalent of linear force. The point where the object rotates is called the axis of rotation. In physics, torque is simply the tendency of a force to turn or twist.
What is the torque on the dipole when it is perpendicular to the field?
Case(I)→ If the dipole is placed perpendicular to the electric field i.e. θ=90∘, the torque acting on it will be maximum. i.e. Case(II)→ If the dipole is placed parallel to the electric field i.e. θ=0∘ or θ=180∘, the torque acting on it will be minimum.
How does torque on the dipole in uniform field depends on its orientation?
Derivation of Torque on an Electric Dipole
Let it be placed in a uniform electric field of strength E such that the axis of the dipole forms an angle θ with the electric field. … Notice that the torque is in the clockwise direction (hence negative) in the above figure if the direction of Electric field is positive.
What is the formula for energy stored in a dipole placed in uniform electric field?
3.4: Potential Energy of a Dipole in an Electric Field. P.E=−pEcosθ=−p⋅E. This is negative when θ is acute and positive when θ is obtuse.
Does an electric dipole always experience a torque when placed in a uniform electric field explain?
When a dipole is placed in a uniform electric field and dipole vector direction is not parallel to field direction, each chargs of dipole experiences a force. Magnitude of the two forces are equal but in opposite direction. … Hence in uniform field, dipole experiences only torque.