Motors and Generators Flashcards
What is the benefit of Lenz’s Law.
It allows you to predict the direction of the current being generated by a magnet.
What is the use of Faraday’s Law?
It allows you to predict when a voltage will be generated by a magnet.
EMF = -(change in flux)/(change in time)
Define electromagnetic induction.
The use of magnetism to create electricity.
State the purpose of a commutator.
To flip the direction of the current in order to maintain the direction of the torque.
Describe the right hand rule for determining the force on a wire in a magnetic field.
Palm flat with thumb pointing out.
Fingers in the direction of the field, thumb in the direction of the current.
Palm will point in the direction of the force.
State the equation for determining the force on a wire in a magnetic field.
F = BIlsinØ
Define torque.
The turning force applied to an object.
State the equation of torque.
τ = Fd
What is the armature of a motor?
The iron core and loop(s) of coils that are free to rotate.
What is the function of the brushes of a motor?
To conduct the current onto the commutator without restricting rotation.
What is the purpose of the iron core of a motor?
To increase the intensity of the magnetic field around the coils.
Why must the iron core of a motor be made out of iron?
Because it is the lightest ferromagnetic metal.
