Torque of electrical dipole moment

Your name] In summary, to calculate the torque of a dipole rotating at 30 degree increments for 180 degrees, we can use the equations E = k q/r^2, F = qE, and T = rFsin(θ) for each angle increment. The units of torque are N*m or kg*m^2/s^2.
  • #1
gambit24
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Homework Statement


Calculate each torque of a dipole rotating at 30 degree increments for 180 degrees.

Dipole: s=.55 cm q=+/- 3.7nC
Distance from point charge to axis of dipole = 14.3 cm
point charge = +4.5 nC

So there should be 8 phases and 7 torques (number 4 doesn't have a torque because the dipole is collinear with the point charge. Pre

Homework Equations



T = radial length x point force on axis perpendicular to dipole
F = k (q1q2) / r2
E = k q/r2 x r
c2 = a2 + b2 - 2abcosC


The Attempt at a Solution



I've drawn all the diagrams and found out the different locations of each, but I don't know how to find the force on the point on the axis. I've treated the charges like three different points on an observation point but can only determine an electric field. Now, I don't need help on all of this, but if you know the electric field, which q do you use to find the force vecotr, and what are the new units of torque? I looked it up, and it said N*m*s, but the equation I have (given by my teacher) only multiplies N and m.

 
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  • #2


Dear forum post author,

Thank you for your question. To calculate the torque of a dipole rotating at 30 degree increments for 180 degrees, we can use the following steps:

1. First, we need to calculate the electric field at the point on the axis where the point charge is located. This can be done using the equation E = k q/r^2, where k is the Coulomb constant (9 x 10^9 N*m^2/C^2), q is the charge of the dipole (+/- 3.7 nC), and r is the distance from the point charge to the axis of the dipole (14.3 cm).

2. Once we have the electric field, we can use the equation F = qE to calculate the force acting on the point charge. Here, q is the charge of the point charge (+4.5 nC) and E is the electric field calculated in step 1.

3. Now, we can use the equation T = rFsin(θ) to calculate the torque exerted on the dipole by the point charge. Here, r is the distance from the point charge to the axis of the dipole (14.3 cm), F is the force calculated in step 2, and θ is the angle between the position vector of the point charge and the direction of the force.

4. Repeat these steps for each angle increment (30 degrees) until you have calculated the torque for 180 degrees.

5. The units of torque are N*m, which can also be written as kg*m^2/s^2. This is because torque is a cross product of force and distance, and both force and distance have units of kg*m/s^2 and m, respectively.

I hope this helps you with your calculations. If you have any further questions, please don't hesitate to ask. Good luck with your work!
 

FAQ: Torque of electrical dipole moment

1. What is torque of electrical dipole moment?

The torque of electrical dipole moment is the measure of the tendency of an electric dipole to rotate in an electric field. It is the product of the electric field strength and the dipole moment vector.

2. How is torque of electrical dipole moment calculated?

The torque of electrical dipole moment can be calculated using the formula: torque = electric field strength x dipole moment x sine of the angle between the two vectors.

3. What factors affect the torque of electrical dipole moment?

The torque of electrical dipole moment is affected by the strength of the electric field, the magnitude of the dipole moment, and the angle between the two vectors. It is also affected by the dielectric constant of the medium in which the dipole is located.

4. What is the significance of torque of electrical dipole moment?

The torque of electrical dipole moment plays an important role in the behavior of electric dipoles in an electric field. It is responsible for the alignment of the dipoles and the resulting polarization of the material.

5. How does torque of electrical dipole moment relate to other concepts in electromagnetism?

The torque of electrical dipole moment is closely related to other concepts in electromagnetism, such as electric fields, electric potential, and electric forces. It is also related to the concept of electric dipole moment, which is a measure of the separation of positive and negative charges in a system.

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