1. The electric property that represents the electrical “pressure” across two points in a circuit is called:
   a. current.
   b. resistance.
   c. voltage.
   d. power.
   
   
2. The electric property that represents the amount of electricity moving in a circuit is called:
   a. current.
   b. resistance.
   c. voltage.
   d. power.
   
   
3. The electric property that represents the opposition to electricity moving in a circuit is called:
   a. current.
   b. resistance.
   c. voltage.
   d. power.
   
   
4. If you connect four 1K resistors in series, what is the total resistance of the circuit?
   a. 1,000
   b. 2,000
   c. 3,000
   d. 4,000
   
   
5. The VA rating of a transformer tells you how much power it is capable of delivering.
   a. True
   b. False
   
   
6. If you connect four 1K resistors in parallel, what is the total resistance of the circuit?
   a. 250
   b. 500
   c. 1,000
   d. 4,000
   
   
7. Connecting batteries in series increases the overall voltage.
   a. True
   b. False
   
   
8. What is the resistance of a resistor with brown, black, and red bands?
   a. 100
   b. 200
   c. 1,000
   d. 2,200
   
   
9. If the fourth band of a resistor is gold, then its tolerance is 10 percent.
   a. True
   b. False
   
   
10. In order to test a fuse, you must remove it from the circuit.
    a. True
    b. False
    
    
11. What are the first 3 bands of a 2.2K resistor?
    a. brown, black, red
    b. red, red, red
    c. brown, red, black
    d. black, brown, red
    e. brown, brown, brown
    
    
12. Standard electrical power in the United States operates on a frequency of 60 Hz.
    a. True
    b. False
    
    
13. Ohm’s law can be expressed as voltage = current x resistance.
    a. True
    b. False
    
    
14. The voltage drop of a circuit is determined by the resistance of the wire and the current flow.
    a. True
    b. False
    
    
15. How much current will flow in a circuit with a 12 VDC source connected to a 1K load?
    a. 12 amps
    b. 1.2 amps
    c. 0.12 amps
    d. 0.012 amps

What’s Wrong with This?

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Wally `Larman installed an access system that used a magnetic lock on one door. He needed to check the amount of current the lock was drawing so that he could troubleshoot a system problem. To do this, Wally took out his volt Ohm meter (VOM) and connected it as shown in this diagram, but was unable to read the current draw. Can you see what Wally did wrong and what he must do to correct the problem?

5-Minute Tech Quiz Answers

1. c

2. a

3. b

4. d — When connecting resistors in series, the total resistance is the sum of all of the resistors in the circuit. In this case, 1K + 1K + 1K + 1K = 4K, which is 4,000 ohms.

5. a — The VA rating shows the voltage x current available. Because power can be simply represented by voltage x current, the higher the VA rating, for a fixed voltage, the higher the current available.

6. a

7. a — Connecting batteries in series will increase the overall voltage. Connecting batteries of the same voltage in parallel increases the available standby time.

8. c

9. b — Gold represents a tolerance of 5 percent. Silver’s tolerance is 10 percent.

10. b — You can test a fuse in circuit by setting your meter on voltage and placing the leads across the fuse. If the fuse is good, you will read 0 volts.

11. b

12. a

13. a — This formula can be used to calculate any item as long as you have the remaining two values.

14. a

15. d — According to Ohm’s law (voltage = current x resistance), 12 = current x 1000, or current = 12/1000, which equals 0.012 amps. This also can be referred to as 12 mA.

Answer to: What's Wrong with This?

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Wally’s problem is caused by the way he connected his VOM and how he set the VOM selector switch. In order to measure current, you must use the amp and comm terminals and set the meter to one of the DCA ranges. Because the current draw is unknown, it is best to start with the switch set to high DCA and use the low DCA setting only if the amount of current is within the low range. Wally should reconnect his meter as shown below, set the range switch and check the current draw. It is important to make sure that you properly set the range selector switch and use the correct terminals, since failure to do so may damage the VOM.