# electronics technician

posted by .

19. In a solenoid, where is the magnetic field strongest?
A. Outside the coil C. At the north pole
B. Inside the coil D. At the south pole
20. What is a typical coil voltage for a low-voltage relay circuit?
A. 2 VDC C. 12 VDC
B. 5 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. C. axis.
B. neutral line. 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 C. 50 ampere-turns
B. 38 ampere-turns D. 600 ampere-turns
25. Which of the following relative permeability values describes a vacuum?
A. 1 C. 100
B. 50 D. 1,000
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 C. Static theory
B. Conventional 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. C. polyform magnet.
B. rare earth 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. C. 45 ampere-turns.
B. 35 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 C. Carbon brushes
B. Armature poles D. Plungers
14. The opposition to magnetic flux as it flows through a magnetic circuit is
A. reluctance. C. permeability.
B. hysteresis. 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 Flemingâ€™s right-hand rule for generator action of electromagnetic induction, the forefinger
points in the direction of the
A. current flow. C. coils windings.
B. conductor motion. D. magnetic flux.
17. What part of a relay is used to support the major components of the relay?
A. Armature C. Contact spring
B. Frame 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. C. part of a closed circuit.
B. moving slowly. D. large enough in diameter.
19. In a solenoid, where is the magnetic field strongest?
A. Outside the coil C. At the north pole
B. Inside the coil D. At the south pole
20. What is a typical coil voltage for a low-voltage relay circuit?
A. 2 VDC C. 12 VDC
B. 5 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. C. axis.
B. neutral line. 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 C. 50 ampere-turns
B. 38 ampere-turns D. 600 ampere-turns
25. Which of the following relative permeability values describes a vacuum?
A. 1 C. 100
B. 50 D. 1,000

• electronics technician -

Inside the coil and no way any of us is going to do all your work for you.

## Similar Questions

1. ### physics induced voltage

A 500 turn solenoid with a length of 20 cm and a radius of 1.5 cm carries a current of 2.0 A. A second coil of four turns is wrapped tightly about this solenoid so that it can be considered to have the same radius as the solenoid. …
2. ### physics induced voltage

A 500 turn solenoid with a length of 20 cm and a radius of 1.5 cm carries a current of 2.0 A. A second coil of four turns is wrapped tightly about this solenoid so that it can be considered to have the same radius as the solenoid. …
3. ### Physics

I have a 250- turn circular coil of wire, 0.10 m in diameter, perpendicular to a 0.050 T magnetic field as shown below. I flip the coil 180 degrees in 1/30 of a second. What is the average voltage created across the ends of the coil?
4. ### Physics

You have a coil with 20 loops inside a magnetic field generator that is temporarily generating a field that has a rate of change of -0.25. The other end of this coil is wrapped around a core with 15 turns. How many turns must a second …
5. ### PHYSICS

You have a coil with 20 loops inside a magnetic field generator that is temporarily generating a field that has a rate of change of -0.25. The other end of this coil is wrapped around a core with 15 turns. How many turns must a second …
6. ### physics

A circular coil with a radius of 25 cm has 20 turns. The coil is oriented perpendicularly to a magnetic field whose initial magnitude is 3.2 T. Suddenly, the magnetic field vanishes in 0.4 s. a. What is the initial magnetic flux in …
7. ### physics

You have a coil with 20 loops inside a magnetic field generator that is temporarily generating a field that has a rate of change of -0.25. The other end of this coil is wrapped around a core with 15 turns. How many turns must a second …
8. ### physics

You have a coil with 20 loops inside a magnetic field generator that is temporarily generating a field that has a rate of change of -0.25. The other end of this coil is wrapped around a core with 15 turns a second coil wrapped around …
9. ### physics

You have a coil with 20 loops inside a magnetic field generator that is temporarily generating a field that has a rate of change of -0.25. The other end of this coil is wrapped around a core with 15 turns. How many turns must a second …
10. ### physics

A magnetic needle is disposed inside a horizontal coil. In the abscence of any electric current the needle is observed to get oriented in a direction perpendicular to the x'x of the coil. a) what is the direction of the terrestrial …

More Similar Questions