Motors and Generators - Core Flashcards
What is torque?
Torque is the turning effect of a force.
What is the motor effect?
It is the action of a force experienced by a current carrying conductor in an external magnetic field.
What is the Torque equation?
It is the product of the tangential component of the force and the distance the force is applied from the axis of rotation.
-Torque = Fd
The SI unit is N.m (Newton metre)
What is commutator?
It is a device for reversing the direction of a current flowing through an electric circuit, e.g. the coil of a motor
What is electromagnetic induction?
It is the generation of an emf and/or electric current through the use of a magnetic field.
What is a galvanometer?
It is an instrument for detecting small electrical currents.
What is induction?
It can be defined as a process where one object with magnetic or electrical properties can produce the same properties in another object without making physical contact.
What is magnetic flux?
It is the amount of magnetic field passing through a given area and is measured in weber (Wb)
What is the strength of a magnetic field also known as?
Magnetic flux density.
What is back emf?
It is an electromagnetic force that opposes the main current flow in a circuit. When the coil of a motor rotates, a back emf is induced in the coil due to its motion in the external magnetic field.
What is a transformer?
It is a magnetic circuit with two multi-turn coils wound onto a common coil which can increase or decrease AC voltages.
What is the armature?
It is the frame around which the coil of wire is wound, which rotates in the motors magnetic field.
When is the right-hand grip rule used?
It is used to find the direction of a magnetic field around a straight current-carrying conductor
What is an eddy current?
It is a circular or whirling current induced in a conductor that is stationary in a changing magnetic field, or that is moving through a magnetic field.
What is a universal motor?
It is a series-wound motor that may be operated on either AC or DC electricity.
