1. If the current through a heater coil is 5 amp and the supply voltage is 120 volts, the coil resistance is
A. 0.04 ohm.
B. 24 ohms.
C. 110 ohms.
D. 575 ohms.
2. The amount of current flowing in a circuit can be measured by
A. an ammeter.
B. a voltmeter.
C. a neon test lamp.
D. an ohmmeter.
3. Which one of the following letters is used in formulas as the symbol for voltage?
4. The conductors in electrical devices are commonly made of
5. The energy used by an appliance which operates at 240 volts at 15 amp for 4 hr. is
A. 0.92 kwhr.
B. 3.45 kwhr.
C. 14.4 kwhr.
D. 60.0 kwhr.
6. What is the voltage in a circuit with a resistance of 12 ohms and a current of 20 amp?
A. 0.58 volt
B. 1.74 volts
C. 120 volts
D. 240 volts
7. If an appliance does NOT work at all when you plug it in and turn the switch on, the appliance circuit is
8. To read the line voltage supplied to an appliance, you should connect the voltmeter
A. in series with the power supply.
B. between the grounded wire and the water pipe.
C. across the power supply.
D. between terminals of two adjacent circuit parts.
9. The best method for testing the continuity of each part of an appliance uses
A. a voltmeter.
B. an ammeter.
C. an ohmmeter.
D. a wattmeter.
10. A 2000-watt heater connected to a 120-volt circuit will draw a current of
A. 5.75 amp.
B. 15 amp.
C. 16.67 amp.
D. 23 amp.
11. What type of fault causes an appliance to blow a fuse when the appliance is turned on?
A. An open circuit
B. Too much resistance
C. A short circuit
D. Too high a voltage
12. Which one of the following conditions is unfavorable for the use of an ohmmeter?
A. Voltage is supplied to the appliance
B. The appliance is grounded
C. Moisture is in the insulation
D. The appliance circuit is shorted
13. A series circuit in an appliance consists of
A. several branches carrying independent currents.
B. more than one part connected across the same terminals.
C. several parts connected end to end.
D. more than one path carrying the current.
14. Which one of the following components is used to change an AC voltage to a lower or higher value?
15. A full-wave bridge rectifier uses how many diodes?
16. An NPN transistor is correctly biased and turned on if the
A. base is negative.
B. collector is negative.
C. collector is positive with respect to the emitter and negative with respect to the base.
D. collector is the most positive lead followed by the base.
17. When an SCR turns ON, it acts like a(n)
B. resistor and capacitor in series.
C. electronic switch and rectifier.
D. bridge rectifier.
18. Which one of the following IC digital gates requires a high on both inputs to output a high?
19. Which one of the following IC gates will have a low output if either of the inputs are high?
20. A microprocessor runs an internal program called a(n)
A. operating system.
B. scratchpad memory.
C. instruction chain.
21. A resistor with the color bands brown, red, red and silver will have a resistance of
A. 120 ohms.
B. 1,200 ohms.
C. 2,100 ohms.
D. 6,400 ohms.
22. What type of diagram chart in a service manual can be used to easily service an electronic circuit board with ICs?
23. An LED display device uses how many segments to create the number 8?
24. When testing transistors, how much minimum voltage difference should be seen across the base-emitter junction?
A. 0.1 VDC
B. 0.4 VDC
C. 0.6 VDC
D. 0.9 VDC
25. When you are forward-bias testing a diode with a digital VOM, the red test lead should be placed on which lead of the diode?