DC Motors: Correcting Armature Reaction and Torque Production

Play an AI-generated podcast conversation about this lesson

What is the term for the difference between the magnetic poles of the earth and the true north and south?

Magnetic variation

Angle of declination (correct)

Magnetic deviation

Polar displacement

What is the characteristic of ferromagnetic materials?

They are only magnetized when an electric current is applied

They are easily magnetized (correct)

They can be magnetized but only temporarily

They cannot be magnetized at all

What is the symbol used to represent magnetic lines of force?

ψ (psi)

Β (beta)

Φ (phi) (correct)

λ (lambda)

What is the behavior of like poles when they interact with each other?

They repel each other Signup and view all the answers

What type of material is copper classified as?

Diamagnetic Signup and view all the answers

What is the primary function of the commutator in a DC motor?

To maintain the correct polarity in the armature windings Signup and view all the answers

What is the effect of Counter EMF on a DC motor?

It opposes the applied EMF Signup and view all the answers

What determines the amount of torque produced by a DC motor?

The strength of both the magnetic field of the pole pieces and the armature Signup and view all the answers

What is the purpose of interpoles in a DC motor?

To correct armature reaction Signup and view all the answers

What is the characteristic of a Series Motor?

High torque and poor speed characteristics Signup and view all the answers

What is the primary mechanism by which a DC motor produces torque?

Forces of attraction and repulsion of magnetism Signup and view all the answers

What is the primary factor in determining the strength of an electromagnetic field?

The number of turns of wire around the core material Signup and view all the answers

What is the term for the ability of a core material to become magnetized?

Permeability Signup and view all the answers

When current stops flowing, what happens to the core material?

It remains magnetized for a period of time Signup and view all the answers

What is the purpose of the left-hand rule in electromagnetism?

To determine the polarity of an electromagnet Signup and view all the answers

What are the three systems for measuring magnetism?

English, CGS, and MKS Signup and view all the answers

What is the purpose of the Commutator in a DC generator?

To change the AC in the armature into DC Signup and view all the answers

What type of armature winding is used for higher voltage lower current operations?

Wave wound Signup and view all the answers

What is the term for the point at which there is 0 volts present in the commutator?

Neutral plane Signup and view all the answers

What are the three main types of field windings in a DC generator?

Series, Shunt, and Compound Signup and view all the answers

What is the main principle behind the operation of a DC generator?

Magnetic induction Signup and view all the answers

What is the function of the Brushes in a DC generator?

To connect the armature to the outer circuit Signup and view all the answers

What is the function of the shunt field relay in a DC motor?

To disconnect power to the armature if shunt field current drops below a certain value Signup and view all the answers

What is the unit of power equivalent to 1 Horsepower?

746W Signup and view all the answers

What is the purpose of a hall effect sensor in a brushless DC motor?

To indicate the exact position of the rotation of the armature Signup and view all the answers

What is the correct way to reverse the direction of rotation of a DC motor?

By changing the 2 leads of the armature or the field, but not both Signup and view all the answers

What is the characteristic of a short shunt compound motor?

The shunt field is in parallel with the armature only Signup and view all the answers

What is the purpose of the right-hand rule in motors?

To determine the direction of thrust and the magnetic field and current Signup and view all the answers