08600300



08600300

|. A circuit contains a 10 µF capacitor and a 30 µF capacitor connected in parallel. What is the total capacitance of the circuit?|

|A. 7.5 µF |

|B. 20 µF |

|C. 40 µF |

|D. 47 µF |

| |

|2. What is the time constant of a 2 mH inductor and a 200 W resistor connected in series? |

|A. 10 msec |

|B. 1 msec |

|C. 10 µsec |

|D. 1 µsec |

| |

|3. Which of the following dielectric materials has the highest dielectric constant? |

|A. Porcelain |

|B. Oil |

|C. Paraffined paper |

|D. Distilled water |

| |

|4. What type of capacitor has great stability and is up to three times smaller than a standard electrolytic capacitor? |

|A. Tantalum |

|B. Paper |

|C. Mica |

|D. Ceramic |

| |

|5. What is the time constant of a 0.05 µF capacitor connected in series with a 200 kW resistor? |

|A. 1 s |

|B. 0.1 s |

|C. 0.01 s |

|D. 10 s |

| |

|6. What is the total inductance of a circuit that contains two 10 µH inductors connected in parallel? |

|A. 5 µH |

|B. 8 µH |

|C. 15 µH |

|D. 20 µH |

| |

|7. An inductor stores a charge |

|A. in the electric field between its plates. |

|B. as a magnetic field in its dielectric. |

|C. as a magnetic field surrounding the conductor. |

|D. in an insulating material in the circuit. |

| |

|8. If an RC circuit is supplied with 24 VDC and the circuit is in its third time constant, how much voltage would be present |

|across the capacitor? |

|A. 20.71 VDC |

|B. 22.77 VDC |

|C. 23.50 VDC |

|D. 22.80 VDC |

| |

|9. What type of capacitor uses aluminum oxide as its dielectric? |

|A. Mica |

|B. Ceramic |

|C. Paper |

|D. Electrolytic |

| |

|10. A circuit contains a 10 pF capacitor and a 50 pF capacitor connected in parallel. What is the total capacitance of this |

|circuit? |

|A. 8.3 pF |

|B. 25 pF |

|C. 50 pF |

|D. 60 pF |

| |

|11. A circuit contains a 20 µF capacitor and a 60 µF capacitor connected in series. What is the total capacitance of the circuit?|

|A. 12 µF |

|B. 15 µF |

|C. 30 µF |

|D. 80 µF |

| |

|12. In an RC circuit, after which of the following time constants is a capacitor considered to be fully charged? |

|A. The first |

|B. The third |

|C. The fifth |

|D. The fourth |

| |

|13. What is the typical insulation resistance for a mica capacitor? |

|A. 1 MW |

|B. 10 KW |

|C. 1,000 MW |

|D. 10,000 µW |

| |

|14. What type of meter is used to directly find the capacitance value of an unknown capacitor or to check the condition of a |

|known capacitor? |

|A. LCR meter |

|B. VOM meter |

|C. Megohm meter |

|D. Oscilloscope |

| |

|15. An RC circuit contains a 1,000 W resistor and a 0.1 µF capacitor. What is the time constant of this circuit? |

|A. 0.01 s |

|B. 0.0001 s |

|C. 1 s |

|D. 0.1 s |

| |

|16. An electronic circuit has a 60 mH inductor and a 30 mH inductor connected in parallel. What is the total inductance of the |

|circuit? |

|A. 90 mH |

|B. 75 mH |

|C. 35 mH |

|D. 20 mH |

| |

|17. Which of the following capacitor types has the lowest insulation resistance and therefore, the highest leakage current? |

|A. Mica |

|B. Ceramic |

|C. Electrolytic |

|D. Tantalum |

| |

|18. Which of the following values is equal to one picofarad? |

|A. 1 × 10-3 F |

|B. 1 × 10-6 F |

|C. 1 × 10-10 F |

|D. 1 × 10-12 F |

| |

|19. On an electrolytic or paper capacitor, what does the black band indicate? |

|A. That the capacitor's negative lead is near the band |

|B. That the capacitor has a value less than 10 mF |

|C. That the capacitor's voltage rating is less than 100 VDC |

|D. That the capacitor is color coded to military specifications |

| |

|20. A mica capacitor has in order, the color codes red, orange, and yellow. What is the capacitance value of this capacitor in |

|microfarads? |

|A. 0.23 µF |

|B. 2.3 µF |

|C. 23 µF |

|D. 230 µF |

| |

|21. After the third time constant, what is the current in an inductor if the steady state circuit current is 10 amps? |

|A. 7.43 A |

|B. 8.60 A |

|C. 9.490 A |

|D. 10.00 A |

| |

|22. What is the time constant of a 5 mH inductor and a 200 W resistor connected in series? |

|A. 100 µs |

|B. 10 µs |

|C. 25 µs |

|D. 0.25 µs |

| |

|23. What is the purpose of placing a large electrolytic capacitor in the output side of a power supply? |

|A. To rectify the AC current |

|B. To remove AC ripple from the DC output |

|C. To hold a charge after the supply is turned off |

|D. To prevent the DC from reversing polarity |

| |

|24. An inductor can be placed in series with a motor to provide |

|A. braking for the motor. |

|B. heat reduction in the motor windings. |

|C. faster motor response to driver signals. |

|D. less current feedback to the driver. |

| |

|25. What action should always be taken before working on a circuit with an electrolytic capacitor or another large capacitor? |

|A. Disconnect the bleeder resistor. |

|B. Place the VOM's leads directly to the capacitor. |

|C. Check the capacitor with an LCR meter. |

|D. Discharge the capacitor. |

08600400

|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. |

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|B. |

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|C. |

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|D. |

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|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 |

| |

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