# Recent questions tagged digital-logic

1
A sequential circuit using D flip-flop and logic gates is shown in Figure, where $X$ and $Y$ are the inputs and $Z$ is the output. The circuit is $\text{S-R}$ Flip-flop with inputs $X = R$ and $Y=S$ $\text{S-R}$ Flip-flop with inputs $X = S$ and $Y=R$ $\text{J-K}$ Flip-flop with inputs $X = J$ and $Y=K$ $\text{J-K}$ Flip-flop with inputs $X = K$ and $Y=J$
2
A $4$ bit ripple counter and a $4$ bit synchronous counter are made using flip-flops having a propagation delay of $10$ ns each. If the worst case delay in the ripple counter and the synchronous counter be $R$ and $S$ respectively, then $R = 10$ ns, $S = 40$ ns $R = 40$ ns, $S = 10$ ns $R = 10$ ns, $S = 30$ ns $R = 30$ ns, $S = 10$ ns
3
A sequential circuit using D flip-flop and logic gates is shown in Figure, where $X$ and $Y$ are the inputs and $Z$ is the output. The circuit is $\text{S-R}$ Flip-flop with inputs $X = R$ and $Y=S$ $\text{S-R}$ Flip-flop with inputs $X = S$ and $Y=R$ $\text{J-K}$ Flip-flop with inputs $X = J$ and $Y=K$ $\text{J-K}$ Flip-flop with inputs $X = K$ and $Y=J$
4
A $4$ bit ripple counter and a $4$ bit synchronous counter are made using flip-flops having a propagation delay of $10$ ns each. If the worst case delay in the ripple counter and the synchronous counter be $R$ and $S$ respectively, then $R = 10$ ns, $S = 40$ ns $R = 40$ ns, $S = 10$ ns $R = 10$ ns, $S = 30$ ns $R = 30$ ns, $S = 10$ ns
1 vote
5
A decimal has $25$ digits. The number of bits needed for its equivalent binary representation is approximately $50$ $74$ $40$ $60$
6
In a ripple counter using edge-triggered $JK$ flip-flops, the pulse input is applied to Clock input of all flip-flops $J$ and $K$ input of one flip-flop $J$ and $K$ input of all flip-flops Clock input of one flip-flop
7
How many $2$-input multiplexers are required to construct a $2^{10}$ input multiplexer? $1023$ $31$ $10$ $127$
8
The number of columns in a stateable for a sequential circuit with $’m’$ flip flops and $’n’$ input is $m+n$ $m+2n$ $2m+n$ $2m+2n$
9
In a ripple counter using edge-triggered $JK$ flip-flops, the pulse input is applied to Clock input of all flip-flops $J$ and $K$ input of one flip-flop $J$ and $K$ input of all flip flops Clock input of one flip-flop
10
A decimal has $25$ digits. The number of bits needed for its equivalent binary representation is approximately, $50$ $74$ $40$ $60$
11
The possible number of Boolean function of $3$ variables $X,Y$ and $Z$ such that $f(X,Y,Z) = f(X’,Y’,Z’)$ $8$ $16$ $64$ $32$
1 vote
12
The smallest integer that can be represented by an $8$-bit number in $2$'s complement form is : $-256$ $-128$ $-127$ $0$
13
The number $(25)_6$, in base $6$ is equivalent to _________ in binary number system. $11001$ $10001$ $11000$ $10000$
1 vote
14
In Boolean algebra $1+1+1+1\dots\dots 800$ times ones $=$ ______ . $1$ $0$ $11$ $800$
15
Which of the following logic expression is incorrect? $1\oplus0=1$ $1\oplus1\oplus0=1$ $1\oplus1\oplus1=1$ $1\oplus1=0$
1 vote
16
1 vote
17
The output of a sequential circuit depends on present inputs only past inputs only both present and past inputs present outputs only
1 vote
18
In a ripple counter using edge triggered $JK$ flip-flops, the pulse input is applied to the clock input of all flip-flops clock input of one flip-flop $J$ and $K$ inputs of all flip-flops $J$ and $K$ inputs of one flip flop
1 vote
19
A decimal number has $30$ digits. Approximately, how many digits would the binary representation have? $30$ $60$ $90$ $120$
20
The result of the subtraction $FD​_{16} - ​88_{16​}$ is $75_{16}$ $65_{16}$ $5E_{16}$ $10_{16}$
1 vote
21
How many RAM chips of size $(256K \times 1 \text{ bit})$ are required to build $1$M Byte memory? $8$ $10$ $24$ $32$
22
Disadvantage of dynamic RAM over static RAM is higher power consumption. variable speed. need to refresh the capacitor charge every once in two milliseconds. higher bit density.
23
The Circuit is equivalent to: EX-OR Gate NAND Gate OR Gate AND Gate
1 vote
24
How many inputs are required in Full Adder Circuit? $2$ $3$ More than two inputs None of the above
1 vote
25
What will be the final output of D flip-Flop if the input string is $0010011100$? $1$ $0$ Don’t Care None of the above
1 vote
26
Which will be the equation of simplification of the given K-map? $AB' + B'CD' + A'B'C'$ $AB' + A'B'D' + A'B'C'$ $B'D' + AB' + B'C'$ $B'D' + A'B'C' + AB'$
1 vote
What is $2$'s complement of $(101)​_3​$? $(010)_3$ $(011)_3$ $(121)_3$ $(121)_2$
How many Addition and Subtraction are required if you perform multiplication of $5$ (Multiplicand) and $-30$(Multiplier) using Booth Algorithm? $2,1$ $1,2$ $1,1$ $2,2$
The Decimal equivalent of the Hexadecimal number $(AC7B)​_{16​}$ is: $32564$ $44155$ $50215$ $43562$