physics Flashcards
a magnetic field is a region where magnetic materials experience……
a force
What are magnetic field lines used for?
to show the magnetic field lines
North to south or south to north
North to south
Is the field uniform when placing two magnetics next to each other
yessir
does north attract north
nosir
do both poles attract magnetic materials
yessir
Name 3 magnetic materials
Iron, cobalt, nickel
When magnetic materials are brought near to a magnets magnetic field, that materials…
acts like a magnet
When is the magnetism induced?
When a magnetic material is brought near a magnet.
how do i get to increase the magnetic inducement?
get the magnet close.
what are two ways you could see the magnetic field lines of a bar magnet
1) compasses
2) iron fillings
What does an electric current in a current create
a magnetic field around it
What is the magnetic field dependent on
the direction of the current
what is a straight current carrying wire made up of
concentric circles
what is similar to the magnetic field of a flat circular coil of wire
the magnetic field of a bar magnet
magnetic field of a solenoid
strong and uniform
What would you call a magnetic material if it looses its induced magnetism
soft or hard
example of a soft and hard magnetic?
iron –> soft
Steel –> hard
Why is iron used in transformers
its used because of its property, it can magnetize and demagnetize 50 times a second.
how do I increase the strength of the magnetic field around a solenoid
adding a magnetically soft iron core through the middle of the coil
Explain the motor effect
when a current carrying wire is put between magnetic poles, the two magnetic fields affect one another , this will result force on the wire. This will also cause the wire to move.
will a wire experience a force if it runs along a magnetic field
no
What’s a good way of showing the direction of the force
apply current to the set of rails inside of a horseshoe magnet, a bar is then placed on the rail which completes the circuit.
magnitude?
magnetic strength
what increases with the magnitude of the circuit.
the magnitude of the magnetic field, and the current passing through the conductor.
what happens when you reverse the current or the magnetic field.
you reverse the direction of the magnetic force
name the thumb, first finger and second finger in Fleming’s left-hand rule.
1) thu-M-b –> Motion
2) -F-irst finger –> Field
3) se-C-ond finger –> Current
Dynamo effect.
electromagnetic induction to generate electricity using energy from kinetic energy stores is the dynamo effect.
real life example of a the dynamo effect
turbine
from the abbreviation EM Induction, what is EM Induction
Electromagnetic Induction
Name two different occasions where you get EM Induction
1) Coil of wire moves through a magnetic field
2) The magnetic field through an electrical conductor changes
Transformer
A transformer is a device that transfers electric energy from one alternating-current circuit to one or more other circuits, either increasing (stepping up) or reducing (stepping down) the voltage.
how many coils do transformers have?
✌️, the primary and secondary joined with a soft iron core
How do transformers work?
When alternating voltage is applied across the primary coil, the soft iron core magnetizes and demagnetizes quickly,. This induces an alternating voltage in the secondary coil.
Induction in physics
The process of generating current in a conductor by placing it in a changing magnetic field is called induction.
the ratio between primary and secondary voltages is the same as the ration between…
the number of turns on the primary and secondary coils
difference between step up and step down transformers
step up increase the voltage, they have more turns on the secondary coil than the primary coil.
step down transformers decrease the voltage, they have more turns on the primary coil than the secondary coil.
transformer equation?
Input (primary) voltage / Output (secondary) voltage
Number of turns on Primary / Number of turns on secondary
Turns ratio
number of turns on the secondary coil /number of turn on the primary coil
power supplied formula?
Power = Voltage X Current
voltage, current formula?
primary voltage x primary current = secondary voltage x secondary current
aka
Vp Ip = Vs Is
what are steep up and step down transformers used for
transmitting electricity across the country
