Digital Computer Electronics — Part 1 MCQs with Explanations

To convert a hexadecimal number to its decimal equivalent, you need to understand the place values in hexadecimal. In hexadecimal , the digit positions represent powers of 16, starting from 16^0 on the right. The number 3F in hexadecimal can be broken down as follows: 3 is in the 16^1 position, so its value is 3 * 16 = 48. F is in the 16^0 position. In hexadecimal, F equals 15, so its value is 15 * 1 = 15. Adding these values together gives 48 + 15 = 63. Therefore , the decimal equivalent of 3FH is 63.

Let inputs be A and B. Inverting each input gives A′ and B′ to the AND gate. The AND gate outputs A′ · B′. Now, the output inverter changes A′ · B′ into (A′ · B′)′. By De Morgan’s law: (A′ · B′)′ = A + B. A + B is the OR function , not NOR. The NOR function would be (A + B)′, which is not what we have here. Therefore: Adding inverters to each input and the output of an AND gate produces an OR gate.

When you add an inverter (NOT gate) to the inputs of an AND gate, you create a logic gate known as a NAND gate . The NAND gate performs the logical AND operation on its inputs and then negates (inverts) the output. In other words, it gives the opposite result of an AND gate. The truth table for a 2-input NAND gate is as follows: A B Output 0 0 1 0 1 1 1 0 1 1 1 0 As you can see, the output is 1 for all input combinations except when both inputs are 1. Therefore, the correct answer is Option B: NAND .

1111012 is the correct answer to “Conversion of decimal number 61 10 to it's binary number equivalent is”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

switches connected in parallel is the correct answer to “An OR gate can be imagined as”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

4A16 is the correct answer to “Conversion of an octal number 112 8 to hexadecimal number is”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

JK flip-flop accepts both inputs 1 is the correct answer to “The functional difference between SR flip-flop and JK flip-flop is that”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

words, high is the correct answer to “The inverter OR gate and AND gate are called decision-making elements because they can recognize some input _____ while disregarding others. A gate recognizes a word when its output is _____”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

OR gate is the correct answer to “A positive AND gate is also a negative”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

gray code is the correct answer to “In which code the successive code characters differ in only one bit position”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

2D16 is the correct answer to “Conversion of binary number 101101 2 to hexadecimal is”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

their collecting sequences is the correct answer to “ASCII and EBCDIC differ in”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

it is controlled by voltage rather than by current, so that it requires very little current at the control terminal is the correct answer to “A p- channel enhancement type MOSFET performs much the same function as a PNP transistor, except that”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

OR is the correct answer to “De Morgan's second therm says that NAND gate is equivalent to a bubbled _____ gate.”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

variations is the correct answer to “When a transistor is cut off or saturated, transistor _____ have almost no effect”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

1000 0000 0000 0111 is the correct answer to “Express -7 as 16-bit signed binary numbers.”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

high, reset is the correct answer to “With an RS latch a high S and low R sets the output to _____ ; a low S and a high R _____ the output to low.”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

complimentary is the correct answer to “Flip-flop outputs are always”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

0.6 and 3.5 V is the correct answer to “The output 0 and 1 levels for TTL logic family is approximately”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

Standard is the correct answer to “A _____ TTL device can sink up to 16mA and can source up to 400 MA.”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

1100 1010 0110 0100 is the correct answer to “What is the 2's complement of 0011 0101 1001 1100 number”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

Truth is the correct answer to “Digital design often starts by constructing a _____ table.”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

F is the correct answer to “The hexadecimal digits are 0 to 9 and A to _____”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

Option "has 128 characters, including 32 control characters" is the correct answer for this question under Digital Computer Electronics.

0 is the correct answer to “An OR gate has 6 inputs. What is the only input word that produces a 0 output”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

Flowchart is the correct answer to “A diagram that illustrates the ore (Logic) of functions in a progran called a”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

100 is the correct answer to “The Gray code for decimal 7 is”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

decay time is the correct answer to “The time required for a pulse to decrease from 90 to 10 percent of its maximum value is known as”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

A1716 is the correct answer to “Conversion of binary number 101000010111 2 to hexadecimal number is”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

NMOS, CMOS is the correct answer to “_____dominates the LSI field, and _____ is used extensively where lowest power consumption is necessary.”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

9910 is the correct answer to “Conversion of an octal number 143 8 to its decimal number is”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

both (a) and (b) is the correct answer to “How many inputs signals can a gate have”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

multiplexer is the correct answer to “A combinational logic circuit which is used when it is desired to send data from two or more source through a single transmission line is known as”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

4916 is the correct answer to “Conversion of binary number 1001001 2 to hexadecimal is”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

CMOS is the correct answer to “Which logic family dissipates the minimum power”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

wires is the correct answer to “A bus is a group of _____ carrying digital signals.”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

X + YZ is the correct answer to “The simplified form of the Boolean expression (X + Y + XY)(X + Z) is”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

AND is the correct answer to “De Morgan's first theorem says that a NOR gate is equivalent to a bubbled _____ gate.”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

1012 is the correct answer to “Addition of 10 2 and 11 2 is”. This question is standard in competitive examination syllabi for Digital Computer Electronics.

6 is the correct answer to “How many bits are required to encode all twenty six letters ten symbols, and ten numerals”. This question is standard in competitive examination syllabi for Digital Computer Electronics.