[SBE] concepts test

[chscherer at everestkc.net]

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From  "jack leishman" <k8xx at chartermi.net> 

Hello, This a 50 question conceptual test.  It contains many questions relative to broadcast engineering. It
is one of 12, with each one getting somewhat more complicated, but all are
closely related to broadcasting.  I know I have always enjoyed quizzes, so I
thought I'd pass this on. I have enjoyed the recent thread on what it takes
to be an engineer. It is the main reason for the SBE and its ability to keep
tests relevant is critical. I am certain 1/2 of the questions will pertain
quite closely. This is my first ever post to SBE.  Hope it works! Jack CSRE
K8XX 



                       Conceptual Test Number Four

1. Choosing wire with less capacitance per foot will
a. cause poorer high frequency response.
b. increase the bandwidth.
c. lower the data thoughput.
d. result in using closer spaced conductors.

2. A transformer will
a. match impedances.
b. step power up or down.
c. boost the available power.
d. All of the above

3. A capacitor is marked 104 and 50 V.
a. It is a 0.1 uF
b. It is rated 100,000 pF at 50 volts.
c. It is a 104 uF and has a maximum 50 V rating.
d. Both a and b are correct.

4. When placing rectifier diodes in series,
a. it is necessary to place a low value resistor in the string.
b. high value resistors should be parallel to each diode.
c. the PRV or PIV rating is lowered.
d. the current rating will go up. 

5. In an inverting op-amp circuit, the feedback resistor is 220k and the input resistor is 10k.
a. The gain is 23
b. The input impedance is about 10,000 ohms
c. The gain is about 20dB.
d. All of the above are true.

6.  A cavity resonator
a. has a high “Q” low bandwidth.
b. is used in combiners, circulators and duplexers.
c. is tuned by varying the cavity dimensions.
d. all of the above

7. If a 120 VAC line must maintain voltage regulation to 5%, what is the highest total conductor resistance that can be used if the load current is 12 amps?
a. .120 ohms
b. .24 ohms
c. .48 ohms
d. .96 ohms

8. The phase to ground voltage in 208 volt three-phase ‘Y” is
a. 120 VAC
b. 173 VAC
c. 240 VAC
d. 277 VAC

9. If a radio is receiving 0.2 uV into its 50 ohm front end, what is the total gain if the audio output is 5 watts?
a. can not be determined
b. about 146 dB
c. 2.5 million
d. nearly 250 dB

10. Which of the following is _not_ true of meters?
a. DMMs typically have 10 megohms input resistance on all ranges.
b. A VOM may typically have 10k/volt input resistance.
c. a 1 milliampere meter is rated at 1000 ohms/volt.  
d. All of the above are correct.

11.  What is the voltage across a 10 uF capacitor after 1 time constant if it is allowed to charge through a 100k resistor to a 15 volt supply?
a. nearly 15 volts
b. about 1.5 volt
c. almost 9.5 volts
d. slightly over 5.5 volts.

12. Which of the following is incorrect?
a. Cell phones operate in the .8-2 GHz range
b. C band satellites are in the 4 GHz range
c. Channel 2 television is about 55 MHz
d. none of the above

13. What is the capacitive reactance of a 2.2 uF capacitor at 20 hertz?
a. about 400 ohms
b. about 2200 ohms
c. about 1580 ohms
d. about 3600 ohms

14. Which of the following is _not_ a common resistor value?
a. 120
b. 150
c. 2.2k
d. 275

15. Which of the following is a negative voltage regulator?
a. 7905
b. LM-340-12
c. 7824
d. 4CX15000A

16. In AC wiring, which of the following is _not_ true.
a. The round plug pin is connected to ground.
b. The wider of the two flat pins is neutral.
c. The neutral wire is connected to the circuit breaker.
d. The black wire is the hot wire.

17. a 1/4 wavelength vertical antenna for 1210 kHz is.
a. about 200 feet
b. about 250 meters
c. about 120 meters
d. none of the above

18. The RMS value of a sine wave is
a. the peak value times 1.414
b. the average value X.902
c. the p-p value divided by 2
d. none of the above

19. A 6 bay circularly polarized antenna has a gain of 7 dB.  Its feedline has 2 dB loss. What is the ERP if the final amplifier voltage is 45 volts and its current is 201 amps if the final stage efficiency is 88%?
a. about 10,000 watts
b. about 25,000 watts
c. about 50,000 watts
d. can not be determined from information supplied.

20. A cube style 4PDT relay operates on 12 VDC, has a 430 ohm coil and is switched by a NPN transistor.
a. The coil should have a series diode to clamp back EMF.
b. The coil will require about 28 mA and nearly 335 mW.
c. If all 4 poles are used, the coil current will rise.
d. None of the above


21.  Which of the following is _not_ correct?
a. A short circuit will pass high current.
b. An open circuit will not pass current.
c. Aluminum is a better conductor than copper.
d. A larger diameter wire will have less resistance.

22. Which of the following requires the widest bandwidth?
a. television
b. FM broadcast
c. AM broadcast
d. facsimile

23. If an automobile’s headlights draw 10 amps when on, how long will a fully charged 80 amp-hour battery sustain this approximate load? 
a. About 15 minutes.
b. 2 or 3 hours.
c. About 8 hours
d. About 33 hours.

24. A MOV is 
a. a voltage dependent resistor.
b. suppresses transient surges.
c. available in numerous values and sizes.
d. All of the above

25. Serial connections to a computer may use
a. USB
b. RS-232
c. Firewire
d. Any of the above.

26.  It is desired to couple about a 300-3000 hertz audio signal into a 50k ohm load, what would be the typical minimum value coupling capacitor? 
a. .01 uF
b. .1 uF
c. 1 UF
d. 10uF

27.  Which of the following type of capacitors are used as power supply filter capacitors and subject to drying out?
a. Ceramic
b. Wetalic
c. Electrolytic
d.Tantalum

28. Which of the following is _not_ a common test equipment manufacturer?
a. Hewlett Packard
b. Dynaco
c. Tektonix
d. Fluke

29. Which of the following is _not_ a wireless standard?
a. Bluetooth
b. 802.11 b/g
c. IrDA
d.VoIP

30. Handheld remote controls operate using
a. Infrared
b. RF
c. Either of the above
d. Neither of the above. 

31.  Which is _not_ a commonly used wire nut color?
a. Red
b. Blue
c. Yellow
d. Green

32. A red handle nut driver is commonly  
a. 1/4 inch.
b. 5/16 inch.
c. 3/8 inch.
d. a #2 nut size.

33. Which of the following is _not_ a type of conduit?
a. EMT
b. Romex
c. BX
d. Sealtite

34. Most all simple SCR motor controllers require a
a. series motor.
b. shaded pole motor.
c. split phase motor.
d. synchronous motor.

35.  The waveform across the filter capacitor in a full wave
120 volt, 60 hertz supply is a
a. sine wave.
b. square wave.
c. sawtooth wave.
d. 120 Hertz 1/2 cycle wave.

36. What would be the safe power rating of a 100 ohm resistor if 220 mA is measured through it?
a. 2 watt
b. 5 watt
c. 10 watt
d. 20 watt 

37. If a 1000 ohm/volt meter, used on the 10 volt scale, is connected across one of two series connected 10k resistors placed across a 10 volt supply, what will the meter read? 
a. 3.3 volts
b. 5 volts
c. 10 volts
d. 100 volts

38. Two 1000 uF, 16 volt electrolytic capacitors are placed in parallel, which of the following is correct?
a. The total capacitance will be 500 uF.
b. The voltage rating will be increase to 32 volts.
c. The total capacitance will be 2000 uF.
d. Either a or b is true.

39. What size fuse may typically be used to protect a 120 VAC oscilloscope if it requires 88 watts from the supply?
a. 3/4 amp
b. 1 amp 
c. 2 amp 
d. 5 amp 

40. When measuring a capacitor with an ohmmeter,
a. it will always read infinite resistance.
b. it will show low resistance until it charges.
c. it will only read the leakage resistance.
d. the RX1 range is used.

41.  Which of the following in _not_ commonly found on a DMM?
a. transistor tester
b. temperature tester
c. milliohm tester
d.10-20 amp capability

42. Which of the following is _not_ correct?
a. The “D” cell is commonly used in flashlights.
b. The “AA” alkaline cell will read about 1.6 volts when new.
c. It is common to place batteries in series for more voltage.
d. “C” cell batteries are typically used in digital cameras.

43. A MOSFET is
a. a type of transistor.
b. a type of microwave diode.
c. a type of resettable solid state fuse.
d. used to control AC motor loads.

44. Which of the following is true?
a. The AM broadcast band is from 0.535 to 1.705 MHz.
b. AM is not allowed above 88 MHz..
c. International shortwave is from 30 to 300 MHz.
d. FM is not used below 88 MHz. 

45. Which of the following is _not_ a type of battery?
a. Lithium
b. nickel cadmium
c. nickel metal hydride
d. copper zinc

46. A logic probe does _not_
a. measure CMOS circuits.
b. latch momentary conditions.
c. show high, low and pulse states.
d. display timing relationships.

47.  Which of the following provides optical isolation?
a. 225R15
b. 4N28
c. LM-324
d. NE-3

48. What is telemetry?
a. metrological data sent by radio.
b. pictures sent by a data stream.
c. a type of modulation used in data acquisition.
d. remote reading of circuit values.

49. What would be a common emitter-base voltage reading in a transistor amplifier?
a. .65 volts
b. 1.6 volts
c. less than 0.1 volts in saturation
d. depends on the supply voltage

50. What size fuse would you expect to find in the cigar lighter circuit of a vehicle?
a. 1 amp
b. 5 amp
c. 10 amp
d. 20 amp