Quiznetik
Digital Logic Circuits (DLC) | Set 3
1. Complement of F’ gives back
A. f’
B. f
C. ff
D. ff’
Correct : B. f
2. Decimal digit in BCD can be represented by
A. 1 input line
B. 2 input lines
C. 3 input lines
D. 4 input lines
Correct : D. 4 input lines
3. The number of logic gates and the way of their interconnections can be classified as
A. logical network
B. system network
C. circuit network
D. gate network
Correct : A. logical network
4. EPROM uses an array of
A. p-channel enhancement type mosfet
B. n-channel enhancement type mosfet
C. p-channel depletion type mosfet
D. n-channel depletion type mosfet
Correct : B. n-channel enhancement type mosfet
5. The EPROM was invented by
A. wen tsing chow
B. dov frohman
C. luis o brian
D. j p longwell
Correct : B. dov frohman
6. Address decoding for dynamic memory chip control may also be used for
A. chip selection and address location
B. read and write control
C. controlling refresh circuits
D. memory mapping
Correct : A. chip selection and address location
7. Which of the following describes the action of storing a bit of data in a mask ROM?
A. a 0 is stored by connecting the gate of a mos cell to the address line
B. a 0 is stored in a bipolar cell by shorting the base connection to the address line
C. a 1 is stored by connecting the gate of a mos cell to the address line
D. a 1 is stored in a bipolar cell by opening the base connection to the address line
Correct : C. a 1 is stored by connecting the gate of a mos cell to the address line
8. The check sum method of testing a ROM
A. allows data errors to be pinpointed to a specific memory location
B. provides a means for locating and correcting data errors in specific memory locations
C. indicates if the data in more than one memory location is incorrect
D. simply indicates that the contents of the rom are incorrect
Correct : D. simply indicates that the contents of the rom are incorrect
9. The initial values in all the cells of an EPROM is
A. 0
B. 1
C. both 0 and 1
D. alternate 0s and 1s
Correct : B. 1
10. To store 0 in such a cell, the floating point must be
A. reprogrammed
B. restarted
C. charged
D. power off
Correct : C. charged
11. The major disadvantage of RAM is?
A. its access speed is too slow
B. its matrix size is too big
C. it is volatile
D. high power consumption
Correct : C. it is volatile
12. Which one of the following is used for the fabrication of MOS EPROM?
A. tms 2513
B. tms 2515
C. tms 2516
D. tms 2518
Correct : C. tms 2516
13. How many addresses a MOS EPROM have?
A. 1024
B. 512
C. 2516
D. 256
Correct : C. 2516
14. ROMs retain data when
A. power is on
B. power is off
C. system is down
D. all of the mentioned
Correct : D. all of the mentioned
15. When a RAM module passes the checker board test it is
A. able to read and write only 0s
B. faulty
C. probably good
D. able to read and write only 1s
Correct : C. probably good
16. What is the difference between static RAM and dynamic RAM?
A. static ram must be refreshed, dynamic ram does not
B. there is no difference
C. dynamic ram must be refreshed, static ram does not
D. sram is slower than dram
Correct : C. dynamic ram must be refreshed, static ram does not
17. How many natural states will there be in a 4-bit ripple counter?
A. 4
B. 8
C. 16
D. 32
Correct : C. 16
18. A ripple counter’s speed is limited by the propagation delay of
A. each flip-flop
B. all flip-flops and gates
C. the flip-flops only with gates
D. only circuit gates
Correct : A. each flip-flop
19. One of the major drawbacks to the use of asynchronous counters is that
A. low-frequency applications are limited because of internal propagation delays
B. high-frequency applications are limited because of internal propagation delays
C. asynchronous counters do not have major drawbacks and are suitable for use in high- and low-frequency counting applications
D. asynchronous counters do not have propagation delays, which limits their use in high- frequency applications
Correct : B. high-frequency applications are limited because of internal propagation delays
20. Internal propagation delay of asynchronous counter is removed by
A. ripple counter
B. ring counter
C. modulus counter
D. synchronous counter
Correct : D. synchronous counter
21. How many flip-flops are required to construct a decade counter?
A. 4
B. 8
C. 5
D. 10
Correct : A. 4
22. The terminal count of a typical modulus-10 binary counter is
A. 0000
B. 1010
C. 1001
D. 1111
Correct : C. 1001
23. A ripple counter’s speed is limited by the propagation delay of
A. each flip-flop
B. all flip-flops and gates
C. the flip-flops only with gates
D. only circuit gates
Correct : A. each flip-flop
24. A 4-bit counter has a maximum modulus of
A. 3
B. 6
C. 8
D. 16
Correct : D. 16
25. UP-DOWN counter is a combination of
A. latches
B. flip-flops
C. up counter
D. up counter & down counter
Correct : D. up counter & down counter
26. UP-DOWN counter is also known as
A. dual counter
B. multi counter
C. multimode counter
D. two counter
Correct : C. multimode counter
27. In an UP-counter, each flip-flop is triggered by
A. the output of the next flip-flop
B. the normal output of the preceding flip-flop
C. the clock pulse of the previous flip-flop
D. the inverted output of the preceding flip-flop
Correct : B. the normal output of the preceding flip-flop
28. In DOWN-counter, each flip-flop is triggered by
A. the output of the next flip-flop
B. the normal output of the preceding flip-flop
C. the clock pulse of the previous flip-flop
D. the inverted output of the preceding flip-flop
Correct : D. the inverted output of the preceding flip-flop
29. Binary counter that count incrementally and decrement is called
A. up-down counter
B. lsi counters
C. down counter
D. up counter
Correct : A. up-down counter
30. Once an up-/down-counter begins its count sequence, it
A. starts counting
B. can be reversed
C. can’t be reversed
D. can be altered
Correct : D. can be altered
31. In 4-bit up-down counter, how many flip-flops are required?
A. 2
B. 3
C. 4
D. 5
Correct : C. 4
32. A modulus-10 counter must have _
A. 10 flip-flops
B. 4 flip-flops
C. 2 flip-flops
D. synchronous clocking
Correct : B. 4 flip-flops
33. Which is not an example of a truncated modulus?
A. 8
B. 9
C. 11
D. 15
Correct : A. 8
34. The designation means that the
A. up count is active-high, the down count is active-low
B. up count is active-low, the down count is active-high
C. up and down counts are both active-low
D. up and down counts are both active-high
Correct : A. up count is active-high, the down count is active-low
35. The full form of SIPO is
A. serial-in parallel-out
B. parallel-in serial-out
C. serial-in serial-out
D. serial-in peripheral-out
Correct : A. serial-in parallel-out
36. How can parallel data be taken out of a shift register simultaneously?
A. use the q output of the first ff
B. use the q output of the last ff
C. tie all of the q outputs together
D. use the q output of each ff
Correct : D. use the q output of each ff
37. What is meant by parallel load of a shift register?
A. all ffs are preset with data
B. each ff is loaded with data, one at a time
C. parallel shifting of data
D. all ffs are set with data
Correct : A. all ffs are preset with data
38. After three clock pulses, the register contains
A. 01110
B. 00001
C. 00101
D. 00110
Correct : C. 00101
39. What will be the 4-bit pattern after the second clock pulse? (Right-most bit first)
A. 1100
B. 0011
C. 0000
D. 1111
Correct : C. 0000
40. In digital logic, a counter is a device which
A. counts the number of outputs
B. stores the number of times a particular event or process has occurred
C. stores the number of times a clock pulse rises and falls
D. counts the number of inputs
Correct : B. stores the number of times a particular event or process has occurred
41. A counter circuit is usually constructed of
A. a number of latches connected in cascade form
B. a number of nand gates connected in cascade form
C. a number of flip-flops connected in cascade
D. a number of nor gates connected in cascade form
Correct : C. a number of flip-flops connected in cascade
42. How many types of the counter are there?
A. 2
B. 3
C. 4
D. 5
Correct : B. 3
43. A decimal counter has states.
A. 5
B. 10
C. 15
D. 20
Correct : B. 10
44. Ripple counters are also called
A. ssi counters
B. asynchronous counters
C. synchronous counters
D. vlsi counters
Correct : B. asynchronous counters
45. Synchronous counter is a type of
A. ssi counters
B. lsi counters
C. msi counters
D. vlsi counters
Correct : C. msi counters
46. Three decade counter would have
A. 2 bcd counters
B. 3 bcd counters
C. 4 bcd counters
D. 5 bcd counters
Correct : B. 3 bcd counters
47. BCD counter is also known as
A. parallel counter
B. decade counter
C. synchronous counter
D. vlsi counter
Correct : B. decade counter
48. The parallel outputs of a counter circuit represent the
A. parallel data word
B. clock frequency
C. counter modulus
D. clock count
Correct : D. clock count
49. The time from the beginning of a read cycle to the end of tACS/tAA is called as
A. write enable time
B. data hold
C. read cycle time
D. access time
Correct : D. access time
50. Why did PROM introduced?
A. to increase the storage capacity
B. to increase the address locations
C. to provide flexibility
D. to reduce the size
Correct : C. to provide flexibility
51. Which of the following is programmed electrically by the user?
A. rom
B. eprom
C. prom
D. eeprom
Correct : C. prom
52. PROMs are available in
A. bipolar and mosfet technologies
B. mosfet and fet technologies
C. fet and bipolar technologies
D. mos and bipolar technologies
Correct : D. mos and bipolar technologies
53. Which of the following best describes the fusible-link PROM?
A. manufacturer-programmable, reprogrammable
B. manufacturer-programmable, one-time programmable
C. user-programmable, reprogrammable
D. user-programmable, one-time programmable
Correct : D. user-programmable, one-time programmable
54. How can ultraviolet erasable PROMs be recognized?
A. there is a small window on the chip
B. they will have a small violet dot next to the #1 pin
C. their part number always starts with a “u”, such as in u12
D. they are not readily identifiable, since they must always be kept under a small cover
Correct : A. there is a small window on the chip
55. Which part of a Flash memory architecture manages all chip functions?
A. program verify code
B. floating-gate mosfet
C. command code
D. input/output pins
Correct : B. floating-gate mosfet
56. How much locations an 8-bit address code can select in memory?
A. 8 locations
B. 256 locations
C. 65,536 locations
D. 131,072 locations
Correct : B. 256 locations
57. What is a fusing process?
A. it is a process by which data is passed to the memory
B. it is a process by which data is read through the memory
C. it is a process by which programs are burnout to the diode/transistors
D. it is a process by which data is fetched through the memory
Correct : C. it is a process by which programs are burnout to the diode/transistors
58. Fusing process is
A. reversible
B. irreversible
C. synchronous
D. asynchronous
Correct : B. irreversible
59. The cell type used inside a PROM is
A. link cells
B. metal cells
C. fuse cells
D. electric cells
Correct : C. fuse cells
60. How many types of fuse technologies are used in PROMs?
A. 2
B. 3
C. 4
D. 5
Correct : B. 3
61. Metal links are made up of
A. polycrystalline
B. magnesium sulphide
C. nichrome
D. silicon dioxide
Correct : C. nichrome
62. Silicon links are made up of
A. polycrystalline silicon
B. polycrystalline magnesium
C. nichrome
D. silicon dioxide
Correct : A. polycrystalline silicon
63. During programming p-n junction is
A. avalanche reverse biased
B. avalanche forward biased
C. zener reverse biased
D. zener reverse biased
Correct : A. avalanche reverse biased
64. The full form of FAMOS is
A. floating gate avalanche injection mos
B. float gate avalanche injection mos
C. floating gate avalanche induction mos
D. float gate avalanche induction mos
Correct : A. floating gate avalanche injection mos
65. PROM is programmed by
A. eprom programmer
B. eeprom programmer
C. prom programmer
D. rom programmer
Correct : C. prom programmer
66. The PROM starts out with
A. 1s
B. 0s
C. null
D. both 1s and 0s
Correct : B. 0s
67. For implementation of PROM, which IC is used?
A. ic 74187
B. ic 74186
C. ic 74185
D. ic 74184
Correct : B. ic 74186
68. IC 74186 is of
A. 1024 bits
B. 32 bits
C. 512 bits
D. 64 bits
Correct : C. 512 bits
69. How many memory locations are addressed using 18 address bits?
A. 165,667
B. 245,784
C. 262,144
D. 212,342
Correct : C. 262,144
70. How many address bits are needed to operate a 2K * 8-bit memory?
A. 10
B. 11
C. 12
D. 13
Correct : B. 11
71. What is the bit storage capacity of a ROM with a 1024 × 8 organization?
A. 1024
B. 4096
C. 2048
D. 8192
Correct : D. 8192
72. The logical sum of two or more logical product terms is called
A. sop
B. pos
C. or operation
D. nand operation
Correct : A. sop
73. The expression Y=AB+BC+AC shows the operation.
A. ex-or
B. sop
C. pos
D. nor
Correct : B. sop
74. The expression Y=(A+B)(B+C)(C+A) shows the operation.
A. and
B. pos
C. sop
D. nand
Correct : B. pos
75. The canonical sum of product form of the function y(A,B) = A + B is
A. ab + bb + a’a
B. ab + ab’ + a’b
C. ba + ba’ + a’b’
D. ab’ + a’b + a’b’
Correct : B. ab + ab’ + a’b
76. A variable on its own or in its complemented form is known as a
A. product term
B. literal
C. sum term
D. word
Correct : B. literal
77. Canonical form is a unique way of representing
A. sop
B. minterm
C. boolean expressions
D. pos
Correct : C. boolean expressions
78. There are Minterms for 3 variables (a, b, c).
A. 0
B. 2
C. 8
D. 1
Correct : C. 8
79. Why is a demultiplexer called a data distributor?
A. the input will be distributed to one of the outputs
B. one of the inputs will be selected for the output
C. the output will be distributed to one of the inputs
D. single input gives single output
Correct : A. the input will be distributed to one of the outputs
80. Most demultiplexers facilitate which type of conversion?
A. decimal-to-hexadecimal
B. single input, multiple outputs
C. ac to dc
D. odd parity to even parity
Correct : B. single input, multiple outputs
81. In 1-to-4 demultiplexer, how many select lines are required?
A. 2
B. 3
C. 4
D. 5
Correct : A. 2
82. In a multiplexer the output depends on its
A. data inputs
B. select inputs
C. select outputs
D. enable pin
Correct : B. select inputs
83. In 1-to-4 multiplexer, if C1 = 1 & C2 = 1, then the output will be
A. y0
B. y1
C. y2
D. y3
Correct : D. y3
84. How many select lines are required for a 1-to-8 demultiplexer?
A. 2
B. 3
C. 4
D. 5
Correct : B. 3
85. How many AND gates are required for a 1-to-8 multiplexer?
A. 2
B. 6
C. 8
D. 5
Correct : C. 8
86. Which IC is used for the implementation of 1-to-16 DEMUX?
A. ic 74154
B. ic 74155
C. ic 74139
D. ic 74138
Correct : A. ic 74154
87. The word demultiplex means
A. one into many
B. many into one
C. distributor
D. one into many as well as distributor
Correct : D. one into many as well as distributor
88. Why is a demultiplexer called a data distributor?
A. the input will be distributed to one of the outputs
B. one of the inputs will be selected for the output
C. the output will be distributed to one of the inputs
D. single input to single output
Correct : A. the input will be distributed to one of the outputs
89. In a multiplexer the output depends on its
A. data inputs
B. select inputs
C. select outputs
D. enable pin
Correct : B. select inputs
90. In 1-to-4 multiplexer, if C1 = 0 & C2 = 1, then the output will be
A. y0
B. y1
C. y2
D. y3
Correct : B. y1
91. In 1-to-4 multiplexer, if C1 = 1 & C2 = 1, then the output will be
A. y0
B. y1
C. y2
D. y3
Correct : D. y3
92. What is the addition of the binary numbers 11011011010 and 010100101?
A. 0111001000
B. 1100110110
C. 11101111111
D. 10011010011
Correct : C. 11101111111
93. Perform binary addition: 101101 + 011011 = ?
A. 011010
B. 1010100
C. 101110
D. 1001000
Correct : D. 1001000
94. Binary subtraction of 100101 – 011110 is
A. 000111
B. 111000
C. 010101
D. 101010
Correct : A. 000111
95. Perform multiplication of the binary numbers: 01001 × 01011 = ?
A. 001100011
B. 110011100
C. 010100110
D. 101010111
Correct : A. 001100011
96. 100101 × 0110 = ?
A. 1011001111
B. 0100110011
C. 101111110
D. 0110100101
Correct : C. 101111110
97. On multiplication of (10.10) and (01.01), we get
A. 101.0010
B. 0010.101
C. 011.0010
D. 110.0011
Correct : C. 011.0010
98. Divide the binary numbers: 111101 ÷ 1001 and find the remainder
A. 0010
B. 1010
C. 1100
D. 0011
Correct : D. 0011
99. Divide the binary number (011010000) by (0101) and find the quotient
A. 100011
B. 101001
C. 110010
D. 010001
Correct : A. 100011
100. Binary subtraction of 101101 – 001011 = ?
A. 100010
B. 010110
C. 110101
D. 101100
Correct : A. 100010