Chapter 29 Flashcards
How do the poles of 2 magnets interact?
Like poles repel and unlike poles attract.
What is magnetism?
It is not the same as electricity however it is also a long-range force. All magnets have 2 poles north and south that exerts forces on each other and the poles can be determined by bringing a compass close as the needle will always point north.
What causes the compass needle to move?
The current passing through the wire leads to the compass needles moving whereas normally - without the current they would be pointing the north pole of the earth.
What is a ferromagnetic material?
The atoms align with the magnetic field and it leads to attraction.
What is RHR#1?
Take your right hand and curl your fingers in the direction of the magnetic field and your thumb is in the direction of the magnetic field.
What is RHR#2?
Use the cross product where the A x B is the index and middle finger respectively and the resultant is the thumb.
What is the Biot-Savt Law?
Since current causes magnetic fields, the moving charges cause a magnetic field.
What are magnetic materials?
Materials that are attracted to a magnet.
What happens when the direction of the distance to a point charge is the same as the velocity?
Then the magnetic field is 0T and because the sin(180) = 0.
How does the magnetic field change for a negative point charge?
The direction of the magnetic field reverses due to the charge that is present in the formula for magnetic fields.
How do you find θ?
This is the angle between the distance from the charge and the velocity - by using the right-hand rule you can determine that the angle is 90 degrees.
How do you take the superposition of the magnetic field of a current-carrying wire from a point away from the wire?
The magnetic field is circulating around the wire take a point and make a tangent line which will be the line of the magnetic field at the point away from the field. Continue that step for the other wires and find the sum of the vectors.
What can you use to visibly see the magnetic field?
Iron filings can determine the direction of the magnetic field.
In what direction is the magnetic field from a current-carrying loop?
In the Z-direction or the direction of the distance from the center of the ring.
What is the difference between electric and magnetic force?
The electric force will act on a moving and non-moving charge but the magnetic force can only act on a moving charge.
Can velocity and magnetic field have the same direction?
No the direction cannot be the same.
When is there tangential acceleration?
When the velocity is only changing in direction and the magnitude remains uniform there is no tangential acceleration only centripetal acceleration.
What is the gyro radius?
This is the radius of the cyclotron.
What is torque?
This is the rotation of an looped wire due to a force exerted by a magnetic field.
What determines the direction of the torque?
The direction of the torque is a result of the magnetic force that is exerted by a magnetic field on the top, bottom, and sides.
