* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download For the test over magnetism, you should know:
Survey
Document related concepts
Maxwell's equations wikipedia , lookup
Skin effect wikipedia , lookup
Electromotive force wikipedia , lookup
Mathematical descriptions of the electromagnetic field wikipedia , lookup
Friction-plate electromagnetic couplings wikipedia , lookup
Electromagnetism wikipedia , lookup
Neutron magnetic moment wikipedia , lookup
Magnetic nanoparticles wikipedia , lookup
Magnetic monopole wikipedia , lookup
Electromagnetic field wikipedia , lookup
Lorentz force wikipedia , lookup
Multiferroics wikipedia , lookup
Magnetoreception wikipedia , lookup
Magnetohydrodynamics wikipedia , lookup
Eddy current wikipedia , lookup
Magnetochemistry wikipedia , lookup
Transcript
For the test over magnetism and induction, you should know: 1. How is magnetic force related to distance between poles in Coulomb’s law of magnetic force? 2. How is the magnetic field strength around a current carrying wire related to distance from the wire? 3. Who showed the connection between electricity and magnetism? 4. Draw the magnetic field for a a. simple bar magnet b. current carrying wire. 5. What is the magnetosphere and what is its shape? 6. What is the shape of the earth’s magnetic field and how are the poles situated? 7. What are magnetic domains? 8. How are the domains oriented in a. non-magnetized and b. magnetized iron? 9. What is meant by magnetic declination? 10. Name two similarities and one major difference between electric charges and magnetic poles 11. What type of force occurs between current carrying wires when currents are in the a) same direction or b) opposite directions? 12. What is a solenoid? What is the shape of its magnetic field? 13. How can the magnetic field of a solenoid be intensified? 14. What creates magnetic fields? 15. What are the units of a. magnetic flux b. flux density c. inductance 16. Be able to use the three right hand rules to figure magnetic field direction for a straight wire and a loop or coil of wire if you are given the direction of the current. 17. What is the function of the commutator in a dc motor or generator? 18. What is a galvanometer? 19. How is the direction of the magnetic force directed on a moving charged particle in a magnetic field found? 20. What if the charged particle is in the magnetic field but not moving? 21. Draw the path of a positively charged particle moving left to right in a region of a uniform magnetic field (into or out of the page). How would it be different for a negatively charged particle? 22. Under what conditions will induction occur? 23. What is Faraday’s Law? 24. What does Lenz’s law say about direction of induced current? Be prepared to find the directions of induced currents using Lenz’s law for a loop in a changing magnetic field or a coil with a magnet being inserted or withdrawn. Examples: a. a loop of wire is situated horizontally in an upward directed magnetic field that is decreasing in strength. What is the direction of the induced current in the loop? b. The N pole of a magnet is withdrawn from a solenoid by pulling it upward. What is the direction of the induced current in the solenoid, viewed from above? 25. What type of energy conversions are taking place in motors and generators? 26. If 2 coils are being used to show induction, with 2X as many coils in the secondary as the primary and a battery of 3V DC is connected to the primary, what is the secondary voltage? 27. If a transformer steps up voltage, what happens to the current? 28. Calculate the velocity of a charge given the magnetic force and the magnetic field strength 29. Calculate the external magnetic field strength, given the current and the magnetic force on a wire. 30. A transformer has 2500 turns in primary, 500 turns in secondary, and 120 V AC input. a. Calculate the secondary voltage b. If the secondary draws 1.5 A, what will be the primary current if it is an ideal transformer?