FINALTERM EXAMINATION Spring 2010
CS302- Digital Logic Design (Session - 1) Time: 90 min
M a r k s: 58
Question No: 1 ( M a r k s: 1 ) http://vuzs.net
"A + B = B + A" is __________
► Demorgan’s Law ► Distributive Law ► Commutative Law ► Associative Law
Question No: 2 ( M a r k s: 1 ) http://vuzs.net
The diagram given below represents __________
► Demorgans law
► Associative law
► Product of sum form
► Sum of product form
Question No: 3 ( M a r k s: 1 ) http://vuzs.net
Following is standard POS expression
► True
► False
Question No: 4 ( M a r k s: 1 ) http://vuzs.net
An alternate method of implementing Comparators which allows the Comparators to be easily cascaded without the need for extra logic gates is _______
► Using a single comparator
► Using Iterative Circuit based Comparators
► Connecting comparators in vertical hierarchy
► Extra logic gates are always required.
Question No: 5 ( M a r k s: 1 ) http://vuzs.net
Demultiplexer is also called
► Data selector
► Data router
► Data distributor
Question No: 6 ( M a r k s: 1 ) http://vuzs.net
The operation of J-K flip-flop is similar to that of the SR flip-flop except that the J-K flip-flop ___________
► Doesn’t have an invalid state
► Sets to clear when both J = 0 and K = 0
► It does not show transition on change in pulse
► It does not accept asynchronous inputs
Question No: 7 ( M a r k s: 1 ) http://vuzs.net
A positive edge-triggered flip-flop changes its state when ________________
► Low-to-high transition of clock
► High-to-low transition of clock
► Enable input (EN) is set
► Preset input (PRE) is set
Question No: 8 ( M a r k s: 1 ) http://vuzs.net
A flip-flop is connected to +5 volts and it draws 5 mA of current during its operation, the power dissipation of the flip-flop is
► 10 mW
► 25 mW
► 64 mW
► 1024
Question No: 9 ( M a r k s: 1 ) http://vuzs.net
____________ counters as the name indicates are not triggered simultaneously.
► Asynchronous
► Synchronous
► Positive-Edge triggered
► Negative-Edge triggered
Question No: 10 ( M a r k s: 1 ) http://vuzs.net
74HC163 has two enable input pins which are _______ and _________
► ENP, ENT
► ENI, ENC
► ENP, ENC
► ENT, ENI
Question No: 11 ( M a r k s: 1 ) http://vuzs.net
The divide-by-60 counter in digital clock is implemented by using two cascading counters:
► Mod-6, Mod-10
► Mod-50, Mod-10
► Mod-10, Mod-50
► Mod-50, Mod-6
Question No: 12 ( M a r k s: 1 ) http://vuzs.net
In a state diagram, the transition from a current state to the next state is determined by
► Current state and the inputs
► Current state and outputs
► Previous state and inputs
► Previous state and outputs
Question No: 13 ( M a r k s: 1 ) http://vuzs.net
A synchronous decade counter will have _______ flip-flops
► 3
► 4
► 7
► 10
Question No: 14 ( M a r k s: 1 ) http://vuzs.net
________ is used to minimize the possible no. of states of a circuit.
► State assignment
► State reduction
► Next state table
► State diagram
Question No: 15 ( M a r k s: 1 ) http://vuzs.net
A multiplexer with a register circuit converts _________
► Serial data to parallel
► Parallel data to serial
► Serial data to serial
► Parallel data to parallel
Question No: 16 ( M a r k s: 1 ) http://vuzs.net
The alternate solution for a demultiplexer-register combination circuit is _________
► Parallel in / Serial out shift register
► Serial in / Parallel out shift register
► Parallel in / Parallel out shift register
► Serial in / Serial Out shift register
Question No: 17 ( M a r k s: 1 ) http://vuzs.net
A GAL is essentially a ________.
► Non-reprogrammable PAL
► PAL that is programmed only by the manufacturer
► Very large PAL
► Reprogrammable PAL
Question No: 18 ( M a r k s: 1 ) http://vuzs.net
The output of this circuit is always ________.
► 1
► 0
► A
► 
Question No: 19 ( M a r k s: 1 ) http://vuzs.net
DRAM stands for __________
► Dynamic RAM
► Data RAM
► Demoduler RAM
► None of given options
Question No: 20 ( M a r k s: 1 ) http://vuzs.net
in ____________, all the columns in the same row are either read or written.
►Sequential Access
►MOS Access
►FAST Mode Page Access
►None of given options
Question No: 21 ( M a r k s: 1 ) http://vuzs.net
FIFO is an acronym for __________
► First In, First Out
► Fly in, Fly Out
► Fast in, Fast Out
► None of given options
Question No: 22 ( M a r k s: 1 ) http://vuzs.net
In order to synchronize two devices that consume and produce data at different rates, we can use _________
► Read Only Memory
► Fist In First Out Memory
► Flash Memory
► Fast Page Access Mode Memory
Question No: 23 ( M a r k s: 1 ) http://vuzs.net
A frequency counter ______________
► Counts pulse width
► Counts no. of clock pulses in 1 second
► Counts high and low range of given clock pulse
► None of given options
Question No: 24 ( M a r k s: 1 ) http://vuzs.net
The sequence of states that are implemented by a n-bit Johnson counter is
► n+2 (n plus 2)
► 2n (n multiplied by 2)
► 2n (2 raise to power n)
► n2 (n raise to power 2)
Question No: 25 ( M a r k s: 1 ) http://vuzs.net
Stack is an acronym for _________
► FIFO memory
► LIFO memory
► Flash Memory
► Bust Flash Memory
Question No: 26 ( M a r k s: 1 ) http://vuzs.net
The 4-bit 2’s complement representation of “+5” is _____________
► 1010
► 1110
► 1011
► 0101
Question No: 27 ( M a r k s: 2 )
Explain the erase operation in context of Flash Memory.
Question No: 28 ( M a r k s: 2 )
Explain the difference between 1-to-4 Demultiplexer and 2-to-4 Binary Decoder?
Question No: 29 ( M a r k s: 2 )
Some of the counters (e.g. 74HC163) are called pre-set counters. why?
Question No: 30 ( M a r k s: 2 )
How many bytes will be there in 32 K x 8 memory?
Question No: 31 ( M a r k s: 3 )
Differentiate between truth table and next-state table
Question No: 32 ( M a r k s: 3 )
Name the three types of errors Analogue to Digital converters exhibit during their conversion operation.
Question No: 33 ( M a r k s: 3 )
How can a serial in/parallel out register be used as a serial in/serial out register?
Question No: 34 ( M a r k s: 5 )
Explain the implementation of First In First Out (FIFO) Memory by using RAM.
Question No: 35 ( M a r k s: 5 )
Explain memory read operation with the help of an example
Question No: 36 ( M a r k s: 5 )
Explain the next-state table with the help of a table for any sequential circuit. 
