WUT ARE MAGNETS?
Could you ever create a magnetic monopole? Why or why not?
No. Think of a train, you will always have a front and back no matter how many times you cut it.
What unit measures the strength of a magnetic field?
Tesla
If current is going into the page, how will the induced magnetic field look?
Curl in the clockwise direction
Velocity of a positive charge goes right. The magnetic field is pointed downward. What direction is the magnetic force?
Into the page
Which high school did Mrs. Torres attend?
Redondo Union High School
Draw magnetic field lines for a bar magnet
Should be lines going from N to S
Why might a wire not be creating a magnetic field?
There’s no current flowing through it
*Cancellation of magnetic fields
For electrons traveling to the left in a wire, what do the magnetic field lines look like above the wire? What do they look like below the wire?
Above: out
Below: in
Velocity of a positive charge is to the left. The magnetic field is pointed out of the page. What direction is the magnetic force?
Up
What’s the address of West High School?
20401 Victor St, Torrance, CA 90503
Why aren’t all pieces of iron permanent magnets?
Because they don’t have their domains aligned up
Name at least two differences between an electromagnet and a permanent magnet
Can be turned on and off
Dependent upon electricity
Does not necessarily need to be made with a ferromagnetic element
For a current traveling clockwise in a circle, what does the magnetic field B look like inside the circle? What does B look like outside the circle?
Inside: Xs (into page)
Outside: dots (coming out of page)
When using the RHR #2, when a particle is in a magnetic field, when is the magnetic force zero? (give at least two situations)
V = 0 (charge is stationary)
Q = 0 (particle is not charged)
V & B are parallel (0 degrees) or anti parallel (180 degrees)
What is the animal for the Chinese zodiac for this year?
Snake
How do I get the most flux from a bar magnet? (give at least two ways)
Place surface at one of the poles
Orient it perpendicular
*Get a stronger magnet, stack magnets
How are generators different from motors?
Motors: Electric energy → Mechanical energy
Generators: ME → Electric energy
A current flows in a straight wire toward east.
What are the directions of the magnetic field produced by the current at points above and below the wire?
Above: South
Below: North
A negative particle is shot into a magnetic field. The initial velocity is upwards. The particle curves clockwise. What does that tell us about the direction of the magnetic field?
B points into page
If the particle curves clockwise, that means the force is to the right. This means that the magnetic field must be pointing into the page (use left hand rule)
When was West High School founded?
1962
What makes iron, nickel, and cobalt ferromagnetic?
Iron, nickel, and cobalt have partially filled electron shells (specifically, d-shells) and, crucially, unpaired electrons. According to Hund's Rule, electrons in a subshell will occupy orbitals individually with parallel spins before pairing up. This results in a net magnetic moment for each atom. So, each atom acts like a tiny magnet.
What are at least two ways that I could increase the amount of energy I generate with a generator?
Increase strength of B
Increase # of coils
Increase area of coils
Increase speed of rotation
Optimize orientation (get the most amount of flux)
When placed above a current-carrying straight wire, a compass needle points to the north.
But when placed below the same wire, the needle points to the south.
In which direction is the current flowing in the wire?
West
A conducting slab has current to the right. A B field is applied out of the page. Due to magnetic forces on the charge carriers, the bottom of the slab is at a higher electric potential than the top of the slab. On the basis of this experiment, the sign of the charge carriers that make up the current in the slab is: (+), (-), or “can’t be determined”?
Positive
Because the force is pointed downward. Positive charge is moving in the downward direction → means that there is higher potential at the bottom of the slab – more (+) charge accumulation
For all five periods, how many students do Mr. Ma and Mrs. Torres teach?
32+33+31+33+29 = 158 students