Electromagnetism Flashcards
Where do charges move around a magnet?
From North to South
What is the Principle of Electromagnetism
When electricity current moves through a conductor a magnetic field is created around the conductor.
What is the Right Hand Rule for Conductors?
With the thumb pointing the direction of the current, the fingers show the direction of the field lines.
How do you know what poles are at either end of a Solenoid?
Inside a solenoid, the magnetic field in the centre flows South to North, on the outside, N to S.
What are some factors that affect magnetic fields?
Increase current - increase field strength. Increase #of coils - increase field strength. Inserting a core - (can) significantly increase the magnetic field strength.
What is the Right Hand Rule for Solenoids?
If coil is grasped with fingers curled in direction of current, the thumb points in direction of magnetic field.
What is the Motor Principle?
A current carrying conductor that cuts across external magnetic field lines experiences a force perpendicular to both the magnetic field and the direction of the current. Magnitude of force depends on magnitude of both external field and current as well as angle between conductor and mag. field it cuts across.
What is the Right Hand Rule for Motors?
If fingers of open right hand point in direction of ext. mag. field and thumb points in direction of current, the force on conductor will be in the direction of the right palm.
What is the Law of Electromagnetic Induction?
An electric current is induced in a conductor whenever the magnetic field in the region of the conductor changes.
What is Lenz’s Law?
The direction of the current induced creates a magnetic field that opposes the change that produced it.
How to find current, voltage, power, windings in a transformer?
P=VI, Pp=Ps, Vp/Vs=Np/Ns=Is/Ip
