Quiznetik
Digital Logic Circuits (DLC) | Set 4
1. Which of the following flip-flop is used by the ring counter?
A. d flip-flops
B. sr flip-flops
C. jk flip-flops
D. t flip-flops
Correct : A. d flip-flops
2. ‘shift_reg’ is used to initialize the
A. lsb
B. msb
C. register type
D. register bits
Correct : B. msb
3. How many types of shift operators are there in VHDL?
A. three
B. four
C. five
D. six
Correct : D. six
4. How many types of the data type are there in the ring counter?
A. one
B. two
C. three
D. more than three
Correct : D. more than three
5. In counter universal clock is not used.
A. synchronous counter
B. asynchronous counter
C. decade counter
D. ring counter
Correct : B. asynchronous counter
6. Synchronous counter use global clock, unlike asynchronous counter.
A. one
B. two
C. three
D. zero
Correct : A. one
7. How many different states does a decade counter count?
A. eight
B. nine
C. ten
D. eleven
Correct : C. ten
8. Output values of Moore type FSM are determined by its
A. input values
B. output values
C. clock input
D. current state
Correct : D. current state
9. What happens if the input is high in FSM?
A. change of state
B. no transition in state
C. remains in a single state
D. invalid state
Correct : A. change of state
10. What happens if the input is low in FSM?
A. change of state
B. no transition in state
C. remains in a single state
D. invalid state
Correct : B. no transition in state
11. . In FSM diagram what does circle represent?
A. change of state
B. state
C. output value
D. initial state
Correct : B. state
12. In the FSM diagram, what does arrow between the circles represent?
A. change of state
B. state
C. output value
D. initial state
Correct : A. change of state
13. . In the FSM diagram, what does the information below the line in the circle represent?
A. change of state
B. state
C. output value
D. initial state
Correct : C. output value
14. Moore machine has states than a mealy machine.
A. fewer
B. more
C. equal
D. negligible
Correct : B. more
15. State transition happens in every clock cycle.
A. once
B. twice
C. thrice
D. four times
Correct : A. once
16. Output values of mealy type FSM are determined by its
A. input values
B. output values
C. both input values and current state
D. current state
Correct : C. both input values and current state
17. What kind of output does mealy machine produce?
A. asynchronous
B. synchronous
C. level
D. pulsed
Correct : A. asynchronous
18. States in FSM are represented by
A. bits
B. bytes
C. word
D. character
Correct : A. bits
19. What is the first step in writing the VHDL for an FSM?
A. to define the vhdl entity
B. naming the entity
C. defining the data type
D. creating the states
Correct : A. to define the vhdl entity
20. Which of the following react faster to inputs?
A. sequencer
B. generators
C. mealy machines
D. moore machines
Correct : C. mealy machines
21. What is the first state of FSM?
A. wait loop state
B. initial state
C. output state
D. activate pulse state
Correct : B. initial state
22. Mealy machines have states than Moore machine.
A. fewer
B. more
C. equal
D. negligible
Correct : A. fewer
23. In mealy type FSM, the path is labelled by which of the following?
A. inputs
B. outputs
C. both inputs and outputs
D. current state
Correct : C. both inputs and outputs
24. The process statement used in combinational circuits is called process.
A. combinational
B. clocked
C. unclocked
D. sequential
Correct : A. combinational
25. Why we need to include all the input signals in the sensitivity list of the process?
A. to monitor the output continuously
B. to monitor the input continuously
C. to make the circuit synthesizable by eda tools
D. no special purpose
Correct : B. to monitor the input continuously
26. Shift registers comprise of which flip-flops?
A. d flip-flops
B. sr flip-flops
C. jk flip-flops
D. t flip-flops
Correct : A. d flip-flops
27. In serial input serial output register, the data of is accessed by the circuit.
A. last flip-flop
B. first flip-flop
C. all flip-flops
D. no flip-flop
Correct : B. first flip-flop
28. In PIPO shift register, parallel data can be taken out by
A. using the q output of the first flip-flop
B. using the q output of the last flip-flop
C. using the q output of the second flip-flop
D. using the q output of each flip-flop
Correct : D. using the q output of each flip-flop
29. Four bits shift register enables shift control signal in how many clock pulses?
A. two clock pulses
B. three clock pulses
C. four clock pulses
D. five clock pulses
Correct : C. four clock pulses
30. Time taken by the shift register to transfer the content is called
A. clock duration
B. bit duration
C. word duration
D. duration
Correct : C. word duration
31. Transfer of one bit of information at a time is called
A. rotating
B. serial transfer
C. parallel transfer
D. shifting
Correct : B. serial transfer
32. In gated D latch, which of the following is the input symbol?
A. d
B. q
C. en
D. clk
Correct : A. d
33. Which of the following is true about packages?
A. package is collection of libraries
B. library is collection of packages
C. package is collection of entities
D. entity is collection of packages
Correct : B. library is collection of packages
34. A package may consist of design units.
A. 2
B. 3
C. 4
D. 5
Correct : A. 2
35. Any item declared in a package declaration section are visible to
A. every design unit
B. package body only
C. library containing that package
D. design unit that use the package
Correct : D. design unit that use the package
36. Which of the following is not a in-built package in VHDL?
A. std_logic_1164
B. textio
C. standard
D. std
Correct : D. std
37. Packages increases of the code.
A. reusability
B. readability
C. managing
D. resolution
Correct : A. reusability
38. Which of the following can’t have multiple assignments or drivers?
A. std_logic
B. integer
C. std_ulogic
D. bit
Correct : C. std_ulogic
39. Which of the following is a not a characteristics of combinational circuits?
A. the output of combinational circuit depends on present input
B. there is no use of clock signal in combinational circuits
C. the output of combinational circuit depends on previous output
D. there is no storage element in combinational circuit
Correct : C. the output of combinational circuit depends on previous output
40. Which of the following is not a combinational circuit?
A. adder
B. code convertor
C. multiplexer
D. counter
Correct : D. counter