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Transcript
1. The resistance of a circuit can be found by using one of the following:
A. R=E/I
B. R=I/E
C. R=E/R
D. R=ExI
2. How is the voltage in a DC circuit calculated when the current and resistance is
known?
A. Voltage equals current divided by resistance.
B. Voltage equals resistance divided by current.
C. Voltage equals power divided by current.
D. Voltage equals current multiplied by resistance.
3. How is the resistance in a DC circuit calculated when the voltage and current are
known?
A. Resistance equals current multiplied by voltage.
B. Resistance equals voltage divided by current.
C. Resistance equals power divided by voltage.
D. Resistance equals current divided by voltage.
4. How is the current in a DC circuit calculated when the voltage and resistance is
known?
A. Current equals voltage divided by resistance.
B. Current equals resistance multiplied by voltage.
C. Current equals resistance divided by voltage.
D. Current equals power divided by voltage.
5. Which electrical circuit will have no current?
A. A short circuit.
B. An open circuit.
C. A complete circuit.
D. A closed circuit.
6. Which electrical circuit uses too much current?
A. A dead circuit.
B. A short circuit.
C. A closed circuit
D. An open circuit.
7. If a current of 2 amperes flows through a 50 ohm resistor, what is the voltage
across the resistor?
A. 48 volts.
B. 52 volts.
C. 100 volts.
D. 25 volts.
8. If a 12 volt battery supplies 0.25 amperes to a circuit, what is the circuit’s
resistance
A. 3 ohms.
B. 48 ohms.
C. 12 ohms.
D. 0.25 ohms.
9. Calculate the resistance necessary to drop 100 volts with a current of 0.8
milliamperes:
A. 125 kilohms.
B. 125 ohms.
C. 1250 ohms.
D. 1.25 kilohms.
10. The voltage required to force a current of 4.4 amperes through a resistance of 50
ohms is:
A. 220 volts.
B. 2220 volts.
C. 22.0 volts
D. 0.220 volts.
11. A lamp has a resistance of 30 ohms and a 6 volt battery is connected. The current
flow will be:
A. 2 amperes.
B. 0.5 amperes.
C. 0.005 amperes.
D. 0.2 amperes.
12. What voltage would be required to supply a current of 200 mA, to operate an
electric lamp, which has a resistance of 25 ohms?
A. 5 volts.
B. 8 volts.
C. 175 volts.
D. 225 volts.
13. If a 3 volt battery supplies 300 mA to a circuit, the circuit resistance is:
A. 10 ohms.
B. 9 ohms.
C. 5 ohms.
D. 3 ohms.
14. The total resistance of resistors connected in series is:
A. Greater than the resistance of any one resistor.
B. Less than the resistance of any one resistor.
C. Equal to the highest resistance present.
D. Equal to the lowest resistance present.
15. Five 10 ohm resistors connected in series equals:
A. 50 ohms.
B. 5 ohms.
C. 10 ohms.
D. 1 ohm.
16. Which series combination of resistors would replace a single 120 ohm resistor?
A. six 22 ohm.
B. Two 62 ohm.
C. Five 100 ohm.
D. Five 24 ohm.
17. In a parallel circuit with a voltage source and several branch resistors, how is the
total current related to the current in the branch resistors?
A. It equals the sum of the branch current through each resistor.
B. It equals the average of the branch current through each resistor.
C. It decreases as more parallel resistors are added to the circuit.
D. It is the sum of each resistor’s voltage drop multiplied by the total number of
resistors.
18. A 6 volt battery is connected across three resistances of 10 ohms, 15 ohms and 20
ohms connected in parallel.
A. The current through the separate resistances, when added together, equals the
total current drawn from the battery.
B. The current flowing through the 10 ohm resistor is less than that flowing
through the 20 ohm resistor.
C. The voltage drop across each resistor when added together equals 6 volts.
D. The voltage drop across the 20 ohm resistor is greater than the voltage across
the 10 ohm resistor.
19. Total resistance in a parallel circuit:
A. is always less than the smallest resistance.
B. depends on the IR drop across each branch.
C. could equal the resistance of one branch.
D. depends on the applied voltage
20. Two resistors are connected in parallel and are connected across a 40 volt battery.
If each resistor is 1000 ohms, the total current is:
A. 80 milliamperes.
B. 40 milliamperes.
C. 80 amperes.
D. 40 amperes.
21. If ten resistors of equal value were wired in parallel, the total resistance would be:
A. 10/R
B. R/10
C. 10xR
D. 10+R
22. The total resistance of four 68 ohm resistors wired in parallel is:
A. 12 ohms.
B. 34 ohms.
C. 272 ohms.
D. 17 ohms.
23. Two resistors are in parallel. Resistor A carries twice the current as resistor B,
which means that:
A. the voltage across A is twice that across B.
B. the voltage across B is twice that across A.
C. A has half the resistance of B
D. B has half the resistance of A.
24. The total current in a parallel circuit is equal to the:
A. the source voltage divided by one of the resistive elements.
B. sum of all the currents through all the parallel branches.
C. source voltage divided by the sum of the resistive elements.
D. current in any one of the parallel branches.
25. What is the basic unit of electrical power?
A. The ampere.
B. The volt.
C. The watt.
D. The ohm.
26. If you had a hand-held transceiver that puts out 500 milliwatts, how many watts
would this be?
A. 5.
B. 0.5.
C. 50.
D. 0.02.
27. Why would a large sized resistor be used instead of a smaller one of the same
resistance?
A. For better response time.
B. For higher current gain.
C. For less impedance to the circuit.
D. For greater power dissipation.
28. The resistor that would dissipate the most power would be marked:
A. 100 ohms.
B. 2 ohms.
C. 20 watts.
D. 0.5 watt.
29. Which of the following two quantities should be multiplied together to find
power?
A. Inductance and capacitance.
B. Voltage and inductance.
C. Voltage and current.
D. Resistance and capacitance.
30. Which two electrical units multiplied together give the unit watts?
A. Volts and farad
B. Farads and henrys.
C. Amperes and henrys.
D. Volts and amperes.
31. A resistor in a circuit becomes very hot and starts to burn. This is because the
resistor is dissipating too much:
A. voltage.
B. resistance.
C. current.
D. power.
32. High power resistors are usually large with heavy leads. The size aids the
operation of the resistor by:
A. allowing higher voltage to be handled.
B. increases the effective resistance of the resistor.
C. allowing heat to dissipate more rapidly.
D. making it shock proof.
33. How many watts of electrical power are used by a 12 VDC light bulb which
draws 0.2 ampere?
A. 2.4 watts.
B. 60 watts.
C. 24 watts.
D. 6 watts.
34. What is the word used to describe how fast electrical energy is used?
A. Current.
B. Power.
C. Voltage.
D. Resistance.
35. The DC input power of a transmitter operating at 12 volts and drawing 500
milliamperes would be:
A. 20 watts.
B. 6 watts.
C. 500 watts.
D. 12 watts.
36. When two 500 ohm 1 watt resistors are connected in series, the maximum total
power that can be dissipated by the resistors is:
A. 1 watt.
B. 2 watts.
C. ½ watt.
D. 4 watts.
37. When two 500 ohm 1 watt resistors are connected in parallel, they can dissipate a
maximum total power of:
A. ½ watt.
B. 1 watt.
C. 2 watts.
D. 4 watts.
38. If the voltage applied to two resistors in series is doubled, how much will the total
power change?
A. Increase four times.
B. Decrease to half.
C. Double.
D. No change.
39. If the power is 500 watts and the resistance is 20 ohms, the current is:
A. 2.5 amps.
B. 10 amps.
C. 25 amps.
D. 5 amps.
40. A 12 volt bulb is rated at a power of 30 watts. The current drawn would be:
A. 30/12 amps.
B. 18 amps.
C. 360 amps.
D. 12/30 amps.
41. If two 10 ohm resistors are connected in series with a 10 volt battery, the power
consumption would be:
A. 5 watts.
B. 10 watts.
C. 20 watts.
D. 100 watts.
42. One advantage of replacing a 50 ohm resistor with a parallel combination of two
similarly rated 100 ohm resistors is that the parallel combination will have:
A. the same resistance but lesser power rating.
B. greater resistance and similar power rating.
C. the same resistance but greater power rating.
D. lesser resistance but similar power rating.
43. Resistor wattage ratings are:
A. calculated according to physical size.
B. expressed in joules per second.
C. determined by heat dissipation qualities.
D. variable in steps of 100.
44. If you have light bulbs marked 40 watts, 60 watts and 100 watts, which one will
use electrical energy the fastest?
A. They will all be the same.
B. The 40 watt bulb.
C. The 100 watt bulb.
D. The 60 watt bulb.
45. Power is expressed in:
A. volts
B. amperes
C. watts
D. ohms
46. How is a voltmeter usually connected to a circuit under test?
A. In series with the circuit.
B. In quadrature with the circuit.
C. In phase with the circuit.
D. In parallel with the circuit.
47. How is an ammeter usually connected in a circuit under test?
A. In quadrature with the circuit.
B. In series with the circuit.
C. In phase with the circuit.
D. In parallel with the circuit.
48. What does a multimeter measure?
A. Resistance, capacitance and inductance.
B. Voltage, current and resistance.
C. Resistance and reactance.
D. SWR and power.
49. The correct instrument to measure plate current or collector current of a
transmitter is:
A. an ohmmeter
B. a wattmeter
C. an ammeter
D. a voltmeter
50. Which of the following meters would you use to measure the power supply
current drawn by a small hand-held transistorized receiver?
A. A DC ammeter.
B. An RF ammeter.
C. An RF power meter.
D. An electrostatic meter.
51. When measuring current from a DC power supply, it is true to say that the meter
will act in circuit as:
A. a perfect conductor
B. a low value resistance
C. an extra current drain
D. an insulator
52. When measuring current drawn by a receiver from a power supply, the current
meter should be placed:
A. in series with both receiver power leads
B. in series with one of the receivers power leads
C. in parallel with both receiver power leads
D. in parallel with one of the receiver power leads
53. Potential difference is measured by means of:
A. a wattmeter
B. an ohmmeter
C. a voltmeter
D. an ammeter
54. Voltage drop means:
A. the voltage which is dissipated before useful work is accomplished
B. difference in voltage at output terminals of a transformer
C. voltage between the terminals of a component
D. any point in a radio circuit which has zero voltage
55. The instrument for measuring the flow of electrical current is the:
A. faradmeter
B. wattmeter
C. ammeter
D. voltmeter
56. In measuring volts and amperes, the connection should be made with:
A. the voltmeter in series and the ammeter in parallel
B. the voltmeter in parallel and the ammeter in series
C. both voltmeter and ammeter in series
D. both voltmeter and ammeter in parallel