Hi i need help with this homework?

1.Magnetic flux is pushed through a magnetic path by


A. reluctance.


B. hysteresis.


C. electromotive force.


D. magnetomotive force.





2.Which of the following units is used to measure magnetic flux density?


A. Gauss


B. Maxwell


C. Weber


D. Watt





3.Which of the following is an electromagnetic device that can operate a switch when current flows through its coil?


A. A bar magnet


B. A horseshoe magnet


C. A relay


D. A core





4.The area inside the hysteresis loop represents


A. residual magnetism.


B. magnetic saturation.


C. energy.


D. permeability.





5.If you dip a bar magnet into iron filings, the filings will stick to


A. both poles of the magnet.


B. the whole magnet.


C. only the north pole of the magnet.


D. only the south pole of the magnet.





6.How do lines of magnetic force travel?


A. From the magnet's south pole to its north pole


B. From the magnet's north pole to its south pole


C. From the magnet's neutral line to its poles


D. From the magnet's poles to its neutral line





7.Which of the following is a magnetic material?


A. Glass


B. Paper


C. Wood


D. Iron





8.Which of the following illustrations shows a closed magnetic circuit?


A.





B.








C.








D.














9.In this figure, a conductor is connected to a battery and placed between two compasses. An electric current is then passed through the conductor. In what direction do the north poles of the compasses point?


A. In the same direction as the magnetic lines of force


B. In the opposite direction from the magnetic lines of force


C. In the same direction as the flow of current through the conductor


D. In the opposite direction from the flow of current through the conductor





10.What theory of current flow says that electric current flows from the positive side of the source, through the load, to the negative side of the source?


A. Electron theory


B. Conventional theory


C. Static theory


D. Magnetic theory





11.An artificial magnet made by pressing magnetic powder together under high pressure and temperature is called a


A. powder core magnet.


B. rare earth magnet.


C. polyform magnet.


D. semisteel magnet.





12.If a current of 5 amperes flows through a coil made up of 40 turns of wire, the amount of MMF generated is


A. 8 ampere-turns.


B. 35 ampere-turns.


C. 45 ampere-turns.


D. 200 ampere-turns.





13.Which of the following are used to connect a DC power supply to the armature of a DC motor?


A. Field poles


B. Armature poles


C. Carbon brushes


D. Plungers





14.The opposition to magnetic flux as it flows through a magnetic circuit is


A. reluctance.


B. hysteresis.


C. permeability.


D. resistance.





15.What happens to a magnetic material when further application of MMF brings only a slight change in magnetism in the material?


A. The material begins to heat rather than absorb more magnetism.


B. The material begins to lose its magnetic properties.


C. The material is termed saturated.


D. The material is said to have low hysteresis.





16.When using Fleming's right-hand rule for generator action of electromagnetic induction, the forefinger points in the direction of the


A. current flow.


B. conductor motion.


C. coils windings.


D. magnetic flux.





17.What part of a relay is used to support the major components of the relay?


A. Armature


B. Frame


C. Contact spring


D. Contact set





18.When a voltage is induced on a moving conductor in a magnetic field, current will only flow if the conductor is


A. formed into a coil.


B. moving slowly.


C. part of a closed circuit.


D. large enough in diameter.





19.In a solenoid, where is the magnetic field strongest?


A. Outside the coil


B. Inside the coil


C. At the north pole


D. At the south pole





20.What is a typical coil voltage for a low-voltage relay circuit?


A. 2 VDC


B. 5 VDC


C. 12 VDC


D. 120 VDC





21.Electromagnetic stepping switches operate by


A. pulsing current to the electromagnet.


B. energizing a set and then reset coil.


C. placing 24 VDC on the coil and letting the switch cycle automatically.


D. placing a control voltage on the contacts of the switch.





22.The center of a bar magnet where no magnetic force is present is called the


A. pole.


B. neutral line.


C. axis.


D. keeper.





23.If you double the distance an object is away from a source of magnetism, how much loss will there be in magnetic flux?


A. The flux will be one-half as strong.


B. The flux will be one-quarter as strong.


C. The flux will be one-fifth as strong.


D. The flux will be one-eighth as strong.





24.What is the amount of MMF generated by a 50-turn electromagnetic coil supplied by 12 VDC at a current of one ampere?


A. 12 ampere-turns


B. 38 ampere-turns


C. 50 ampere-turns


D. 600 ampere-turns





25.Which of the following relative permeability values describes a vacuum?


A. 1


B. 50


C. 100


D. 1,000|||1. A


2. C


3. D


4. B


5. B


6. C


7. A


8.


9. A


10. D


11. C


12. A


13. B


14. B


15. D


16. A


17. C


18. C


19. C


20. D


21. B


22. D


23. A


24. B


25. C





I totally just bs-ed it :D do your own work.|||C B B first three I am a graduate in quantum physics