Question 1. How is odd parity generated differently from even parity ?
▶️ The first output is inverted .
▶️ The last output is inverted .
Answers. The last output is inverted
Question 2. In the digital clock project , when does the PM indicator go high ?
▶️ Never
▶️ Going from 11:59:59 to 12:00:00
▶️ Going from 12:59:59 to 01:00:00
▶️ On the falling edge of the clock after enable goes high
Answers. Going from 12:59:59 to 01:00:00
Question 3. Data transfer from I / O to external data memory can only be done with the MOVX command .
▶️ TRUE
▶️ FALSE
Answers. TRUE
Question 4. What is a shift register that will accept a parallel input , or a bidirectional serial load and internal shift features , called ?
▶️ tristate
▶️ end around
▶️ universal
▶️ conversion
Answers. Universal
Question 5. Which of the following expressions is in the sum of – products ( SOP ) form ?
▶️ ( A + B ) ( C + D )
▶️ ( A ) B ( CD )
▶️ AB ( CD )
▶️ AB + CD
Answers. AB+ CD
Question 6. Which of the following circuit parameters would be most likely to limit the maximum operating frequency of a flip – flop ?
▶️ setup and hold time
▶️ clock pulse HIGH and LOW time
▶️ propagation delay time
▶️ clock transition time
Answers. propagation delay time
Question 7. Which term applies to the maintaining of a given signal level until the next sampling ?
▶️ Holding
▶️ Aliasing
▶️ Shannon frequency sampling
▶️ ” Stair – stepping ”
Answers. Holding
Question 8. Which of the following logic families has the shortest propagation delay ?
▶️ S – TTL
▶️ AS – TTL
▶️ OHS – TTL
▶️ HCMOS
Answers. AS – TTL
Question 9. A transducer is a device that : electrical variable
▶️ converts a physical variable to an data
▶️ converts analog data to meaningful
▶️ controls a physical variable
▶️ stores digital data and then processes that data according to a set of specified instructions
Answers. converts a physical variable to an data
Question 10. How many flip – flops are in the 7475 IC ?
▶️ 1
▶️ 2
▶️ 04
▶️ 08
Answers. 04
Question 11. The is defined as the time the output is active divided by the total period of the output signal .
▶️ on time
▶️ off time
▶️ duty cycle
▶️ active ratio
Answers. Duty cycle
12. Question How many address bits are needed to select all memory locations in the 2118 16KX 1 RAM
▶️ 8
▶️ 10
▶️ 14
▶️ 16
Answers. 14
13. Question For a CMOS gate , which is the best speed – power product ? ▶️ 1.4 pJ
▶️ 1.6 pJ
▶️ 2.4pJ
▶️ 3.3 pJ
Answers. 1.4 pJ
14. Question The most commonly used system for representing signed binary numbers is the : ▶️ 2’s – complement system .
▶️ 1’s – complement system .
▶️ 10’s – complement system .
▶️ sign – magnitude system .
Answers. 2’s – complement system
15. Question How many different voltages can be output from a DAC with a 6 – bit resolution ?
▶️ 6
▶️ 7
▶️ 32
▶️ 64
Answers. 64
16. Question Propagation delay time , tPLH , is measured from the
▶️ triggering edge of the clock pulse to the LOW – to – HIGH transition of the output
▶️ triggering edge of the clock pulse to the HIGH – to – LOW transition of the output
▶️ preset input to the LOW – to – HIGH transition of the output ▶️ clear input to the HIGH – to – LOW transition of the output
Answers. triggering edge of the clock pulse to the LOW – to – HIGH transition of the output
17. Question List which pins need to be connected together on a 7493 to make a MOD – 12 counter .
▶️ 12 to 1 , 11 to 3 , 9 to 2
▶️ 12 to 1 , 11 to 3 , 12 to 2
▶️ 12 to 1 , 11 to 3 , 8 to 2
▶️ 12 to 1 , 11 to 3 , 1 to 2
Answers. 12 to 1 , 11 to 3 , 8 to 2
18. Question The output of an exclusive – NOR gate is 1. Which input combination is correct ?
▶️ A = 1 , B = 0
▶️ A = 0 , B = 1
▶️ A = 0 , B = 0
▶️ none of the above
Answers. A = 0 , B = 0
19. Question What is the first thing you will need if you are going to use a macrofunction ?
▶️ A complicated design project
▶️ An experienced design engineer
▶️ Good documentation ▶️ Experience in HDL
Answers Experience in HDL
20 . Question Any number with an exponent of zero is equal to :
▶️ zero
▶️ one
▶️ that number
▶️ ten
Answers. Zero
21. Question What does the discharge transistor do in the 555 timer circuit ?
▶️ charge the external capacitor to stop the timing
▶️ charge the external capacitor to start the timing over again
▶️ discharge the external capacitor to stop the timing
▶️ discharge the external capacitor to start the timing over again
Answers. discharge the external capacitor to start the timing over again
22. Question ALM is the acronym for
▶️ Array Logic Matrix
▶️ Asynchronous Local Modulator
▶️Arithmetic Logic Module
▶️ Adaptive Logic Module
Answers. Adaptive Logic Module
23. Question The commutative law of Boolean addition states that A + B = A x B.
▶️ TRUE
▶️ FALSE
Answers. FALSE
24. Question Internally , a computer’s binary data are almost always transmitted on
▶️ parallel channels , commonly referred to as the : parallel bus
▶️ serial bus
▶️data bus
▶️ memory bus
Answers. Data bus
25. Question A small circle on the output of a logic gate is used to represent the :
▶️ Comparator operation .
▶️ OR operation .
▶️ NOT operation .
▶️ AND operation .
Answers. NOT operation
26. Question For a 4 – bit DAC , the least significant bit ( LSB ) is
▶️ 6.25 % of full scale
▶️ 0.625 % of full scale
▶️ 12 % of full scale
▶️ 1.2 % of full scale
Answers. 6.25 % of full scale
27. Question If an analog signal is to be converted to an 8 – bit resolution , how many comparators are used in a parallel – encoded ADC ?
▶️ 127
▶️ 128
▶️ 255
▶️ 256
Answers. 256
28. Question Why is parallel data transmission preferred over serial data transmission for most applications
▶️ It is much slower .
▶️ It is cheaper .
▶️ It is much faster .
▶️ More people use it .
Answers . It is much faster.
29. Question What is the basic difference between AHDL and VHDL?
▶️ ADHL is used in all PLD’s
▶️ VHDL is used in all PLD’s.
▶️ ADHL is proprietary.
▶️ VHDL is proprietary.
Answers. ADHL is proprietary
30. Question Which statement below best describes the function of a decoder ?
▶️ A decoder will convert a decimal number into the proper binary equivalent .
▶️ A decoder will convert a binary number into a specific output representing a particular character or digit .
▶️ Decoders are used to prevent improper operation of digital systems .
▶️ Decoders are special ICs that are used to make it possible for one brand of
Answers. A decoder will convert a decimal number into the proper binary equivalent .
31. Question How can a digital one – shot be implemented using HDL ?
▶️ By using a resistor and a capacitor
▶️ By applying the concept of a counter
▶️ By using a library function
▶️ By applying a level trigger
Answers. By applying the concept of a counter
32. Question A logic circuit that provides a HIGH output if one input or the other input , but not both , is HIGH , is a ( n ) :
▶️ Ex – NOR gate
▶️OR gate
▶️ Ex – OR gate
▶️ NAND gate
Answers. Ex – OR gate
33. Question The voltages in digital electronics are continuously variable . ▶️ TRUE
▶️ FALSE
Answers.
34. Question . The generic array logic (GAL) device is
▶️ one-time programmable
▶️ reprogrammable
▶️ a CMOS device
▶️ reprogrammable and a CMOS device
Answers. reprogrammable and a CMOS device
35. Question. Which digital system translates coded characters into a more useful form?
▶️ encoder
▶️ display
▶️ counter
▶️ decoder
Answers. decoder
36. Question. Convert BCD 000100100110 to binary
▶️ 1111110
▶️ 1111101
▶️ 1111000
▶️ 1111111
Answers. 1111110
37. Question Solving-11+ (-2) will yield which two’s-complement answer?
▶️ 11110011
▶️ 11111001
▶️ 11101101
▶️ 11101001
Answers. 1111 0011
38. Question. How many flip-flops are in the 7475 IC?
▶️ 1
▶️ 2
▶️ 3
▶️ 4
Answers. 4
39. Question. Which of the following is the most widely used alphanumeric code for computer input and output?
▶️ Gray
▶️ ASCII
▶️ Parity
▶️EBCDIC
Answers. ASCII
40.Question Which of the following logic families has the shortest propagation delay?
▶️ CMOS
▶️ ECL
▶️ BICMOS
▶️ 745XX
Answers. ECL
41. Question The 8051 has 16-bit counter/timers.
▶️ 1
▶️ 2
▶️ 3
▶️ 4
Answers. 2
42. Question What is the function of an enable input on a multiplexer chip?
▶️to apply Vcc
▶️to connect ground
▶️to active the entire chip
▶️to active one half of the chip
Answers. to active the entire chip
42. Question. In a digital clock application, the basic frequency must be divided down to:
▶️ 1 Hz
▶️ 60 Hz
▶️ 100 Hz.
▶️ 1000 Hz.
Answers. 1 Hz