Take this test both before and after reading the 555 article and compare your results.
This type of test is classified as OBJECTIVE or MULTIPLE-CHOICE. It is much more effective than it appears. Multiple-choice can be "off-putting" and decision-making is made more difficult. That's why it is so good. In addition, it is very easy to have computer-scoring and provided enough questions are asked, the results are very accurate. Attempting this type of test will strengthen your knowledge of a topic. By the simple fact that it asks the same information more than once, with the result that the facts are passed to your long-term memory.    

QUESTIONS:



1. The function of Pin 3 is:
Control Voltage
Discharge
Output
Reset
Threshold
Trigger

2. The function of Pin 6 is:
Control Voltage
Discharge
Output
Reset
Threshold
Trigger

3. The function of Pin 5 is:
Control Voltage
Discharge
Output
Reset
Threshold
Trigger

4. The function of Pin 4 is:
Control Voltage
Discharge
Output
Reset
Threshold
Trigger

5. What is the function of the Threshold pin?
  
To charge the capacitor "C"
To discharge the capacitor "C"
To detect when the capacitor is "HIGH"
To detect when the capacitor is "LOW" 

6. What is the function of the Discharge pin?
To charge the capacitor "C"
To discharge capacitor "C"
To detect when the capacitor is "HIGH"
To detect when the capacitor is "LOW"

7. What is the function of the Trigger pin?
To charge the capacitor "C"
To discharge the capacitor "C"
To detect when the capacitor is "HIGH"
To detect when the capacitor is "LOW"

8. What is the function of the Reset pin?
To discharge the capacitor "C"
To reset the chip
To make the output of the chip "HIGH"

9. The Discharge and Output are:
In phase with each other
Out of phase with each other

10. What does pin 6 do?
Charges the capacitor "C"
Discharges the capacitor "C"
Detects the HIGH on capacitor "C"
Detects the LOW on capacitor "C"

11. When pin 2 detects the voltage-level on the capacitor, 
       does the capacitor begin to charge or discharge?
Charge
Discharge

12. What does pin 2 do?
Charges the capacitor "C"
Discharges the capacitor "C"
Detects the HIGH on capacitor "C"
Detects the LOW on capacitor "C"

13. In the following diagram, is the output predominantly 
HIGH or LOW? Remember: Pin 7 and 3 act "in harmony"
   
HIGH
LOW

14. To increase the output frequency of a 555:
Increase the value of capacitor "C"
Decrease the value of capacitor "C"

15. If the resistors in Q13 are swapped, does the output frequency
 change?
It increases
It decreases
Little or no effect

16. What does pin 7 do?
Charges the capacitor "C"
Discharges the capacitor "C"
Detects the HIGH on capacitor "C"
Detects the LOW on capacitor "C" 

17. If the value of R1 is increased:
    
The output frequency increases
The output frequency decreases
The overall frequency does not alter

18. Name the resistor(s) that effect the timing of the "LOW OUTPUT":
R1 and R2
R1 only
R2 only

19. For a 5v circuit, if pin 4 is taken to 1v, does the chip reset?
Yes
No
Cannot be determined

20. When pin 2 detects the voltage-level on the capacitor, 
       what happens to the output?
It goes HIGH
It goes LOW

21. For the following diagram, which resistor(s) controls the "SPACE:"
     
R1
R2
R1 + R2

  22. The maximum frequency of operation for a 555 is:
100kHz
500kHz
5MHz
500Hz 

23. For the following diagram, the Mark:Space ratio will be:
   
Greater than 50%
Less than 50%
Equal
Unable to be determined

Output HIGH (mS) Output LOW (mS) Frequency (kHz)

Calculate the Frequency,  HIGH-interval and LOW-interval 
for a 555 in ASTABLE mode. See answer below for Monostable (Delay):

Delay Sec

24. Use the calculator above to obtain the output frequency of the following circuit:
   
0.0001412kHz
141Hz
141kHz  

25. If the two resistors in Q24 are swapped, the output frequency will:
Increase
Decrease
Remain the same

26. What value resistors with a 100u, will produce a delay of 15
      seconds?
100k plus 33k
47k plus 47k
22k plus 33k

27. What value of delay will 3M3 and 100u produce?:
0.47 sec
3.74 sec
363 secs

28. Which set of values will produce the highest frequency:
100k  22k      10n
10k    4k7    100n
22k   100k     10n
4k7   10k     100n

29. Which set of values will produce the highest frequency:
4k7  1k    1n
2k2  1k    2n2
1k    1k    4n7
10k  1k    10n

30. Which set of values will produce the longest delay:
3M3     47u
1M     100u
470k   220u

31 What type of circuit is shown in the diagram below:
  
Monostable
Astable
Free-Running

32. What is the name of the pin that activates a 555 in Delay mode:
Control
Trigger
Discharge
Threshold

33. Identify the output waveform produced by the following circuit:
  
  
(a)   (b)   (c)   (d)   (e)   (f)

34. Identify the output waveform produced by the following circuit:
  
  
(a)   (b)   (c)   (d)   (e)   (f)

35. Identify the output waveform produced by the following circuit:
  
  
(a)   (b)   (c)   (d)   (e)   (f)

36. If the trigger-pulse in Q34 is held LOW longer than the delay produced by R and C, the output will:
Stay LOW
Stay HIGH
Go LOW after the Delay and remain LOW
Go LOW after the Delay for an instant, then go HIGH

37. Will the following circuit work?
  
Yes
No
A resistor must be connected between pin 2 and 0v rail 
A resistor must be connected between pin 2 and the positive rail  

38. 
  
The circuit will settle with the LED on
The circuit will settle with the LED off
The circuit will oscillate at a high frequency
Unable to be determined 

39. 
  
The circuit will settle with the LED on
The circuit will settle with the LED off
Unable to be determined 

40. 
  
The circuit will settle with the LED on
The circuit will settle with the LED off
The circuit will oscillate
Unable to be determined