CS504

The days of week is an example analog parameter. TRUE. FALSE.

The digital synchronous signal is discrete in both of time and value. TRUE. FALSE.

Digital systems can operate with extreme reliability by using error‐correcting codes. TRUE. FALSE.

The minimum number of bits required to code four distinct elements is four. TRUE. FALSE.

In general, coding requires more bits than conversion. TRUE. FALSE.

The coding of a decimal number between 0 and 9 in BCD needs the same number of bits as the conversion of this decimal number to its equivalent binary value. TRUE. FALSE.

Excess-3 is weighted coding method of decimal numbers where each digit in the decimal number is coded into four bits. TRUE. FALSE.

Self-complementing property means that the 9's complement of a decimal number is obtained directly by changing 1’s to 0's and 0's to 1's in its binary code. TRUE. FALSE.

6311 coding method uses only 10 combinations out of 16 to represent 10 decimal digits (0-9). TRUE. FALSE.

The 7-bit ASCII binary codes takes the decimal range from 0 to 128. TRUE. FALSE.

Parity bit method can detect and correct all single-bit errors. TRUE. FALSE.

Only the odd parity can detect an odd number of bit errors while the even parity cannot. TRUE. FALSE.

Unique truth table but different Boolean equations and logic diagrams can express a function. TRUE. FALSE.

In actual physical gates, if an input changes then the output change occurs instantaneously. TRUE. FALSE.

Switching algebra is a multi-valued form of Boolean algebra. TRUE. FALSE.

The dual of an algebraic expression is obtained by only interchanging + and . symbols. TRUE. FALSE.

An algebraic expression is self-dual when its dual is equal to the algebraic expression itself. TRUE. FALSE.

The absorption theorem states that: (1) X + X’Y = X + Y (2) X . (X’ + Y) = X . Y. TRUE. FALSE.

The De Morgan of an algebraic expression is obtained by taking the dual of the algebraic expression and complementing each literal in it. TRUE. FALSE.

The De Morgan theorem of switching algebra is proved to be generalized to multiple number of Boolean variables. TRUE. FALSE.

Minterm is AND term so it is also called the standard sum. TRUE. FALSE.

Standard product or standard sum are used to express Boolean function in standard form. TRUE. FALSE.

Boolean function of n variables has 2n/2 minterms and 2n/2 maxterms in its truth table. TRUE. FALSE.

(b + a + c) is a valid maxterm of a Boolean function. TRUE. FALSE.

ab is a valid minterm of a Boolean function. TRUE. FALSE.

Minterm evaluates to ‘1’ for its corresponding entry in the Boolean function truth table. TRUE. FALSE.

POM is an abbreviation of “Product of Minterms” canonical form. TRUE. FALSE.

Maxterm is the complement of minterm but not vice-versa. TRUE. FALSE.

The algebraic Boolean function expression: F = Y’ + X’Z’ can be written in SOM canonical form: F = ∑(0, 1, 2, 4, 5). TRUE. FALSE.

The algebraic Boolean function expression: G = A + B’C can be written in POM canonical form: G = ∏(0, 2, 3). TRUE. FALSE.

Given: F’(x, y, z) = ∏ (1, 3, 5, 7), then F(x, y, z) = ∑ (0, 2, 4, 6). TRUE. FALSE.

Given: F’(x, y, z) = ∏ (1, 3, 5, 7), then F(x, y, z) = ∑ (1, 3, 5, 7). TRUE. FALSE.

SOM of n-variable Boolean function is implemented as network of n-input AND gates connected to an OR gate. TRUE. FALSE.

In general, canonical form must have fewer literals than standard form for Boolean function. TRUE. FALSE.

In general, canonical form must have more literals than standard form for Boolean function. TRUE. FALSE.

SOP and POS are simplified forms of SOM and POM respectively. TRUE. FALSE.

Each of AND, OR, XOR and XNOR gates can be extended to have more than two inputs. TRUE. FALSE.

A gate implements a positive logic AND function will implement a negative logic OR function, and vice-versa. TRUE. FALSE.

Circuit optimization is a more formal approach to simplification that requires three cost criteria to measure the simplicity of a circuit. TRUE. FALSE.

Each square in K-map represents a maxterm. TRUE. FALSE.

Each square in K-map represents a minterm. TRUE. FALSE.

On 3-variable K-map, a combined eight adjacent squares represent 0-variable term. TRUE. FALSE.

AND-Invert and Invert-OR both represent NAND gate. TRUE. FALSE.

A 2-level POS circuit can be converted easily to a NAND-NAND implementation. TRUE. FALSE.

A 2-level POS circuit can be converted easily to a SOP implementation. TRUE. FALSE.

NAND and NOR gates are neither commutative nor associative. TRUE. FALSE.

NAND and NOR gates are commutative & associative. TRUE. FALSE.

A NOR gate with one input is an inverter. TRUE. FALSE.

NOR-NOR implementation requires function to be in POM/POS form. TRUE. FALSE.

To implement a Boolean function as two-level NOR-OR circuit, its 0’s in the k-map must be combined into SOP form. TRUE. FALSE.

XOR and XNOR are also known as the odd and even functions respectively. TRUE. FALSE.

XOR and XNOR functions are associative but not commutative. TRUE. FALSE.

Analysis finds out function of given circuit, while design determines circuit of given function. TRUE. FALSE.

The full adder circuit can be implemented using two cascaded half adder circuits. TRUE. FALSE.

When two signed binary numbers are added, an overflow can be detected from the end carry out of the most significant bit position. TRUE. FALSE.

The digital asynchronous signal is ......... in time and ......... in value. discrete - continuous. discrete - discrete. continuous – discrete. continuous – continuous.

The electrical signals in most present‐day digital systems use just ......... discrete values. 2. 3. 4. 5.

The number of bits, n, is required to code at maximum distinct elements. n^3. n * log(n). 2^n. n^2.

A number with n decimal digits is coded with .......... bits in Excess-3. 2n. 4n. n^3. n^2.

he weights of BCD code are ......... 8,4,2,1. 6,3,1,1. 6,4,2,1. 84-2-1.

All the following binary coding methods are self-complementing except ......... BCD. Excess-3. 2421. 84-2-1.

2421 binary coding methods codes each decimal digit into . bits. 9. 6. 4. 2.

The Excess-3 code of the decimal number, (945)10, is .......... 110001111000. 1001100101. 1110110001. 100101000101.

Error correction during transmission of .........-coded decimal digits is easiest of all other binarycodes because only 1 bit changes from one binary value to the next value. BCD. Gray. Excess3. ASCII.

The extended-ASCII uses .........-bit to code 128 elements of the alphanumeric character set. 32. 7. 8. 16.

There are .......... basic binary logical operations. 2. 3. 4. 5.

The decoded decimal value of (100010010111)2 in 84-2-1 coding is ........ (564)10. (871)10. (897)10. (675)10.

An 8-bit binary code is decoded into ......... -digit decimal number using 6432 coding. 4. 2. 3. 6.

The theorem of Boolean algebra states that: (1) X + X = X (2) X . X = X is named. involution. complement. idempotence. identity.

The postulate of Boolean algebra states that: (1) X + Y = Y + X (2) X . Y = Y . X is named ....... associative. distributive. commutative. De Morgan.

The precedence of Boolean operators from the highest to the lowest written in order from the left to the right is .......... NOT, AND, OR, Parentheses. Parentheses, AND, NOT, OR. NOT, Parentheses, AND,OR. Parentheses, NOT, AND,OR.

The ......... theorem states that: AB + A’C + BC = AB + A’C. simplification. consensus. minimization. absorption.

is AND term with every variable present in either true or complemented form. Product. Maxterm. Minterm. Sum.

Standard sum is another name of ...... product. maxterm. sum. minterm.

For ........., ‘1’ in its binary index means that the corresponding variable is normal (not complemented) while ‘0’ means that the corresponding variable is complemented. product. minterm. maxterm. sum.

is a canonical form that expresses Boolean function by “ANDing” its standard sums corresponding to ‘0’ entries in the Boolean function truth table. POM. POS. SOM. SOP.

The equivalent algebraic expression of the canonical form: F(a, b, c, d) = ∏(1, 3, 6, 11) is ... ( b + c + d’ ) . ( b + c’ + d’ ) . ( b’ + c’ + d ) . ( a’ + b + c’ + d’ ). ( a’ + b’ + c’ + d ) . ( a’ + b’ + c + d ) . ( a’ + b + c + d’ ) . ( a + b’ + c + d ). ( a + b + c + d’ ) . ( a + b + c’ + d’ ) . ( a + b’ + c’ + d ) . ( a’ + b + c’ + d’ ). ( c + d’ ) . ( c’ + d’ ) . ( b’ + c’ + d ) . ( a’ + b + c’ + d’ ).

The canonical form: ..........is the equivalent to the following algebraic expression: a’b’c’d’ + a’b’c’d + abc’d’ + abcd. G(a, b, c, d) = ∑(0, 1, 12, 15. G(a, b, c, d) = ∏(0, 1, 12, 15). G(a, b, c, d) = ∏(0, 3, 14, 15). G(a, b, c, d) = ∑(0, 3, 14, 15).

The form of POM or POS is implemented as network from two-levels of .......... gates. ORs-AND. ANDs-AND. ORs-OR. ANDs-OR.

The algebraic expression F(A, B, C) = (B + C).(A + C) is in .......... form. SOP. POS. POM. SOM.

A gate can be extended to multiple inputs if the binary operation it represents is .... commutative and distributive. commutative and associative. associative and distributive. associative and De Morgan.

binary Boolean operations are commutative but not associative, so they are not extendable to more than two inputs. AND and OR. NAND and NOR. Buffer and Inverter. XOR and XNOR.

are known as the odd and even functions respectively. XOR and XNOR. AND and OR. Buffer and Inverter. NAND and NOR.

A gate implements a positive logic OR function will implement a negative logic ......... function. NOR. AND. XNOR. XOR.

F = ( A + C’ ) . ( B’ + C ) . ( A’ + B ) has the following costs: ...... L = 6, G = 8 and GN = 11. L = 6, G = 9 and GN = 12. L = 3, G = 6 and GN = 9. L = 3, G = 9 and GN = 12.

By combining adjacent squares in K-map, we reduce number of literals in an output ... minterm. maxterm. product term. sum term.

On 4-variable K-map, a combined four adjacent squares represent .........-variable term. 0. 2. 3. 4.

The optimum POS of F(W, X, Y, Z) = ∑ (1, 2, 3, 9, 10, 11, 13, 14, 15) is ..... F(W, X, Y, Z) = WZ + WY + X’Z + X’Y. F(W, X, Y, Z) = Y’Z’ + W’X. F(W, X, Y, Z) = ( Y’ + Z’) ( W’+ X ). F(W, X, Y, Z) = ( Y + Z ) ( W + X’ ).

The optimum SOP of F(A, B, C, D) = ∑ (3, 9, 11, 12, 13, 14, 15) + ∑d (1, 4, 6) is ..... F(A, B, C, D) = A’B + B’D’. F(A, B, C, D) = AB + B’D. F(A, B, C, D) = (A + B’) . (B + D). F(A, B, C, D) = (A’ + B’) . (B + D’).

The optimum SOP of F(A, B, C, D) = ∑ (0, 2, 3, 5, 7, 8, 9, 10, 11, 13, 15) has .......... essential prime implicants. 0. 1. 2. 3.

Invert-AND represents ......... gate. NAND. NOR. XOR. XNOR.

AND is equivalent to ......... with inverted inputs. XNOR. XOR. NOR. NAND.

Two-level ......... circuit can be easily converted to NOR-NOR implementation. AND-OR. OR-AND-Invert. AND-OR-Invert. OR-AND.

AND-OR-Invert implementation of a circuit can be easily converted to .... NAND-AND. OR-NAND. NOR-OR. AND-NAND.

is also known as the equivalence function. XNOR. XOR. NOR. NAND.

gates are used for implementing parity generators and checkers circuits. XOR and XNOR. Buffer and inverted. NAND and NOR. AND and OR.

To check for errors in the even parity of 3-bit codes, it is needed to use ..........checker circuit. 3-bit odd function. 4-bit odd function. 3-bit even function. 4-bit even function.

To perform circuit analysis, a ........ must be provided as an input to the analysis process. truth table. logic diagram. Boolean function. problem statement.

The carry output of half adder circuit has the same truth table of ......... gate. AND. OR. NOR. NAND.

The full adder circuit adds ......... bits together. 2. 3. 4. 5.

Overflow occurs if the two binary numbers added are ..... both positive or both negative. both positive. both negative. one of them is positive and the other is negative.

Active-low decoder is implemented with .......... gate. OR. AND. NAND. NOR.

selects binary information from one of many input lines and directs it to a single output line. multiplexer. encoder. decoder. adder.