> For the complete documentation index, see [llms.txt](https://nec-license.gitbook.io/books/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://nec-license.gitbook.io/books/2.-digital-logic-and-microprocessor/mcqs/mcqs-on-digital-logic/set-2.md).
# set-2
#### 51. The binary code of (73)10 is
1. 1010001
2. 1100101
3. 1000100
4. 1001001
Show me the answer
**Answer:** 4. 1001001
**Explanation:**
* The binary representation of the decimal number **73** is **1001001**.
* Therefore, the correct answer is **1001001**.
#### 52. An AND gate will function as OR if
1. All the inputs to the gates are "1"
2. All the inputs are "0"
3. Either of the inputs is "1"
4. All the inputs and outputs are complemented
Show me the answer
**Answer:** 4. All the inputs and outputs are complemented
**Explanation:**
* An **AND gate** will function as an **OR gate** if **all inputs and outputs are complemented**.
* Therefore, the correct answer is **All the inputs and outputs are complemented**.
#### 53. An OR gate has 6 inputs. How many input words are in its truth table?
1. 64
2. 16
3. 32
4. 128
Show me the answer
**Answer:** 1. 64
**Explanation:**
* For an OR gate with **6 inputs**, the number of input words in its truth table is:\
$$2^6 = 64$$
* Therefore, the correct answer is **64**.
#### 54. An OR gate has 6 inputs. What is the only input word that produces a 0 input?
1. 000000
2. 111000
3. 000111
4. 111111
Show me the answer
**Answer:** 1. 000000
**Explanation:**
* The only input word that produces a **0 output** for an OR gate with **6 inputs** is **000000**.
* Therefore, the correct answer is **000000**.
#### 55. An AND gate has 7 inputs. How many input word are in its truth?
1. 64
2. 16
3. 32
4. 128
Show me the answer
**Answer:** 4. 128
**Explanation:**
* For an AND gate with **7 inputs**, the number of input words in its truth table is:\
$$2^7 = 128$$
* Therefore, the correct answer is **128**.
#### 56. An AND gate has 7 inputs, what is the only input word that produces a 1 output?
1. 0000000
2. 1110000
3. 0001111
4. 1111111
Show me the answer
**Answer:** 4. 1111111
**Explanation:**
* The only input word that produces a **1 output** for an AND gate with **7 inputs** is **1111111**.
* Therefore, the correct answer is **1111111**.
#### 57. A NOR gate has or more input signals. All inputs must be … to get a high output
1. Low
2. Some low some high
3. High
4. 1's
Show me the answer
**Answer:** 1. Low
**Explanation:**
* For a **NOR gate**, **all inputs must be LOW** to get a **HIGH output**.
* Therefore, the correct answer is **Low**.
#### 58. A NOR gate recognizes only the input word whose bits are…
1. 0's and 1's
2. 0's
3. 1's
4. 0's or 1's
Show me the answer
**Answer:** 2. 0's
**Explanation:**
* A **NOR gate** recognizes only the input word whose bits are **0's**.
* Therefore, the correct answer is **0's**.
#### 59. The NOR gate is logically equivalent to an OR gate followed by an …
1. AND
2. XOR
3. XAND
4. Inverter
Show me the answer
**Answer:** 4. Inverter
**Explanation:**
* A **NOR gate** is logically equivalent to an **OR gate** followed by an **inverter**.
* Therefore, the correct answer is **Inverter**.
#### 60. De Morgan's first theorem says that a NOR gate is equivalent to a bubbled … gate
1. AND
2. XOR
3. XAND
4. NOR
Show me the answer
**Answer:** 1. AND
**Explanation:**
* De Morgan's first theorem states that a **NOR gate** is equivalent to a **bubbled AND gate**.
* Therefore, the correct answer is **AND**.
#### 61. A NAND gate is equivalent to an AND gate followed by an inverter. All inputs must be…to get a low output
1. Low
2. Some low and some high
3. High
4. 0's
Show me the answer
**Answer:** 3. High
**Explanation:**
* For a **NAND gate**, **all inputs must be HIGH** to get a **LOW output**.
* Therefore, the correct answer is **High**.
#### 62. De Morgan's second theorem says that NAND gate is equivalent to a bubbled ……gate
1. AND
2. XOR
3. XAND
4. OR
Show me the answer
**Answer:** 4. OR
**Explanation:**
* De Morgan's second theorem states that a **NAND gate** is equivalent to a **bubbled OR gate**.
* Therefore, the correct answer is **OR**.
#### 63. An XOR gate recognizes only words with an ……number of 1's
1. Even
2. Different
3. Odd
4. All of the above
Show me the answer
**Answer:** 3. Odd
**Explanation:**
* An **XOR gate** recognizes only words with an **odd number of 1's**.
* Therefore, the correct answer is **Odd**.
#### 64. The 2-input XOR gate has a high output only when the input bits are…
1. Even
2. Low
3. Different
4. High
Show me the answer
**Answer:** 3. Different
**Explanation:**
* A **2-input XOR gate** has a **HIGH output** only when the input bits are **different**.
* Therefore, the correct answer is **Different**.
#### 65. The XOR gates are ideal for testing parity because even-parity words produce a …. Output and odd-parity words produce a ……output
1. Low, high
2. Odd, even
3. High, low
4. Even, odd
Show me the answer
**Answer:** 1. Low, high
**Explanation:**
* **XOR gates** are ideal for testing parity because **even-parity words produce a LOW output** and **odd-parity words produce a HIGH output**.
* Therefore, the correct answer is **Low, high**.
#### 66. An odd-parity generator produces an odd-parity bit to go along with the data. The parity of the transmitted data is ….. An XOR gate can test each received word for parity rejecting words with …. Parity
1. Odd, even
2. Low, high
3. High, low
4. Even, odd
Show me the answer
**Answer:** 1. Odd, even
**Explanation:**
* An **odd-parity generator** produces an **odd-parity bit**, and an **XOR gate** can test each received word for parity, rejecting words with **even parity**.
* Therefore, the correct answer is **Odd, even**.
#### 67. The EXCLUSIVE-NOR gate is equivalent to an ……gate followed by an inverter
1. OR
2. NAND
3. AND
4. XOR
Show me the answer
**Answer:** 4. XOR
**Explanation:**
* The **EXCLUSIVE-NOR gate** is equivalent to an **XOR gate** followed by an **inverter**.
* Therefore, the correct answer is **XOR**.
#### 68. Small-scale integration, abbreviated ….. refers to fewer than 12 gates on the same chip. Medium-scale integration (MSD) means 12 to 100 gates per chip. And large-scale integration (LST) refers to more than ……gates per chip
1. SSI, 75
2. SSI, 1000
3. SSI, 100
4. SSI, 10000
Show me the answer
**Answer:** 3. SSI, 100
**Explanation:**
* **Small-scale integration (SSI)** refers to fewer than **12 gates** on the same chip, **Medium-scale integration (MSI)** refers to **12 to 100 gates**, and **Large-scale integration (LSI)** refers to more than **100 gates**.
* Therefore, the correct answer is **SSI, 100**.
#### 69. The two basic technologies for digital ICs are bipolar and MOS. Bipolar technology is preferred for ...... and ...... whereas MOS technology is better suited to LSI
1. SSI, MSI
2. SSI, LSI
3. MSI, LSI
4. ECL, DTL
Show me the answer
**Answer:** 1. SSI, MSI
**Explanation:**
* **Bipolar technology** is preferred for **SSI** and **MSI**, while **MOS technology** is better suited for **LSI**.
* Therefore, the correct answer is **SSI, MSI**.
#### 70. What is 1's complement of 0000 1111 0010 1101 number?
1. 1111 0000 0010 1101
2. 1111 0000 1101 0010
3. 1111 0000 0010 1101
4. 1111 1100 1010 1100
Show me the answer
**Answer:** 2. 1111 0000 1101 0010
**Explanation:**
* The **1's complement** of **0000 1111 0010 1101** is obtained by flipping all the bits:\
$$1111 0000 1101 0010$$
* Therefore, the correct answer is **1111 0000 1101 0010**.
#### 71. .....has become the most widely used bipolar family
1. DTL
2. ECL
3. TTL
4. MOS
Show me the answer
**Answer:** 3. TTL
**Explanation:**
* **TTL (Transistor-Transistor Logic)** has become the most widely used bipolar family.
* Therefore, the correct answer is **TTL**.
#### 72. .....is the fastest logic family' it's used in high-speed applications
1. DTL
2. ECL
3. TTL
4. MOS
Show me the answer
**Answer:** 2. ECL
**Explanation:**
* **ECL (Emitter-Coupled Logic)** is the fastest logic family and is used in high-speed applications.
* Therefore, the correct answer is **ECL**.
#### 73. .....dominates the LSI field and ....used extensively where lowest power consumption is necessary
1. NMOS, PMOS
2. NMOS, CMOS
3. PMOS, CMOS
4. MOSFET, PMOS
Show me the answer
**Answer:** 2. NMOS, CMOS
**Explanation:**
* **NMOS** dominates the **LSI field**, and **CMOS** is used extensively where the lowest power consumption is necessary.
* Therefore, the correct answer is **NMOS, CMOS**.
#### 74. The 7400 series, also called standard TTL, contains a variety of SSI and ... chips that allow us to build all kinds of digital circuits and systems
1. LSI
2. MOS
3. MSI
4. MOSFET
Show me the answer
**Answer:** 3. MSI
**Explanation:**
* The **7400 series** contains a variety of **SSI** and **MSI** chips.
* Therefore, the correct answer is **MSI**.
#### 75. Standard TTL has a multiple emitter input transistor and a ..... output
1. Totem-pole
2. Register
3. Bipolar
4. Transistor
Show me the answer
**Answer:** 1. Totem-pole
**Explanation:**
* **Standard TTL** has a **multiple emitter input transistor** and a **totem-pole output**.
* Therefore, the correct answer is **Totem-pole**.
#### 76. The 7400-series devices are guaranteed to work reliably over a temperature range of 0 to .... and over a voltage range of 4.75 to 5.25 V
1. 80(^\circ)C
2. 100(^\circ)C
3. 70(^\circ)C
4. 90(^\circ)C
Show me the answer
**Answer:** 3. 70(^\circ)C
**Explanation:**
* The **7400-series devices** are guaranteed to work reliably over a temperature range of **0 to 70(^\circ)C**.
* Therefore, the correct answer is **70(^\circ)C**.
#### 77. A ... TTL device can sink up to 16 mA and can source up to 400MA
1. Low-power
2. Standard
3. High-power
4. Schottky
Show me the answer
**Answer:** 2. Standard
**Explanation:**
* A **standard TTL device** can sink up to **16 mA** and can source up to **400 mA**.
* Therefore, the correct answer is **Standard**.
#### 78. The maximum number of TTL loads that a TTL device can drive reliably over the specified temperature range is
1. Fanout
2. Chip
3. Bipolar
4. Universal logic circuit
Show me the answer
**Answer:** 1. Fanout
**Explanation:**
* The **maximum number of TTL loads** that a TTL device can drive reliably is called its **fanout**.
* Therefore, the correct answer is **Fanout**.
#### 79. Digital design often starts by constructing a ..... table?
1. Standard
2. Truth
3. Two-Stage
4. Two-dimensional
Show me the answer
**Answer:** 2. Truth
**Explanation:**
* Digital design often starts by constructing a **truth table**.
* Therefore, the correct answer is **Truth**.
#### 80. A preliminary guide for comparing the simplicity of logic circuits to count the number of input......leads
1. Wires
2. Transistors
3. Gates
4. Registers
Show me the answer
**Answer:** 2. Transistors
**Explanation:**
* A preliminary guide for comparing the simplicity of logic circuits is to count the number of **transistors**.
* Therefore, the correct answer is **Transistors**.
#### 81. A bus is a group of .....carrying digitals signals
1. Wires
2. Transistors
3. Gates
4. Registers
Show me the answer
**Answer:** 1. Wires
**Explanation:**
* A **bus** is a group of **wires** carrying digital signals.
* Therefore, the correct answer is **Wires**.
#### 82. One way to simplicity the sum-of-products equation is to use Boolean algebra. Another way is the .....map
1. De Morgan
2. Schottky
3. Standard
4. Karnaugh
Show me the answer
**Answer:** 4. Karnaugh
**Explanation:**
* The **Karnaugh map** is another way to simplify the sum-of-products equation.
* Therefore, the correct answer is **Karnaugh**.
#### 83. What are the fundamental products for inputs words ABCD = 0010, ABCD = 1101 and ABCD = 1110?
1. ABCD, ABCD, ABCD
2. ABCD, ABCD, ABCD
3. ABCD, ABCD, ABCD
4. ABCD, ABCD, ABCD
Show me the answer
**Answer:** 3. ABCD, ABCD, ABCD
**Explanation:**
* The fundamental products for the input words **0010**, **1101**, and **1110** are **ABCD**, **ABCD**, and **ABCD**.
* Therefore, the correct answer is **ABCD, ABCD, ABCD**.
#### 84. The ALU carries out arithmetic and numbers rather than decimal numbers
1. Decimal
2. Binary
3. Hexadecimal
4. All of the above
Show me the answer
**Answer:** 2. Binary
**Explanation:**
* The **ALU (Arithmetic Logic Unit)** carries out arithmetic on **binary numbers** rather than decimal numbers.
* Therefore, the correct answer is **Binary**.
#### 85. A half-adder adds....bits
1. 16
2. 19
3. 8
4. 2
Show me the answer
**Answer:** 4. 2
**Explanation:**
* A **half-adder** adds **2 bits**.
* Therefore, the correct answer is **2**.
#### 86. A full-adder adds ....bits and producing a SUM and a....
1. 8, SUBTRACTION
2. 16,DIVIDE
3. 3, CARRY
4. All of the above
Show me the answer
**Answer:** 3. 3, CARRY
**Explanation:**
* A **full-adder** adds **3 bits** and produces a **SUM** and a **CARRY**.
* Therefore, the correct answer is **3, CARRY**.
#### 87. A binary adder is a logic circuit that can add.....binary numbers at a time
1. Hundreds
2. One
3. Thousands
4. Two
Show me the answer
**Answer:** 4. Two
**Explanation:**
* A **binary adder** can add **two binary numbers** at a time.
* Therefore, the correct answer is **Two**.
#### 88. The leading bit stands for the ...and the remaining bits for the ..., is known as signed binary numbers
1. Sign, remainder
2. Value, sign
3. Sign, magnitude
4. Variable, value
Show me the answer
**Answer:** 3. Sign, magnitude
**Explanation:**
* In **signed binary numbers**, the **leading bit** stands for the **sign**, and the **remaining bits** stand for the **magnitude**.
* Therefore, the correct answer is **Sign, magnitude**.
#### 89. Signed binary numbers requires too much hardware. This has led to the use of ... complements to represent negative numbers
1. 1's
2. 3's
3. 2's
4. No
Show me the answer
**Answer:** 3. 2's
**Explanation:**
* **2's complement** is used to represent negative numbers in signed binary numbers to reduce hardware requirements.
* Therefore, the correct answer is **2's**.
#### 90. A 2's-complement adder-subtracter can add or subtract binary numbers. Sign-magnitude numbers represent.....decimal numbers and 2's complements stands for .... Decimal numbers
1. Hexa, sign
2. Positive, negative
3. Sign, hexa
4. Negative, positive
Show me the answer
**Answer:** 2. Positive, negative
**Explanation:**
* **Sign-magnitude numbers** represent **positive decimal numbers**, and **2's complement** represents **negative decimal numbers**.
* Therefore, the correct answer is **Positive, negative**.
#### 91. How many full and half-adders are required to add 16-bit numbers?
1. 8 half-adders, 8 full-adders
2. 16 half-adders, no full-adders
3. Half-adders, 15 full-adders
4. Half-adders, 12 full-address
Show me the answer
**Answer:** 3. Half-adders, 15 full-adders
**Explanation:**
* To add **16-bit numbers**, you need **1 half-adder** and **15 full-adders**.
* Therefore, the correct answer is **Half-adders, 15 full-adders**.
#### 92. Express-7 as 16-bits signed binary numbers
1. 0000 0000 0000 0111
2. 0111 0000 0000 0000
3. 1000 0000 0000 0111
4. 0111 0000 0000 0000
Show me the answer
**Answer:** 3. 1000 0000 0000 0111
**Explanation:**
* The **16-bit signed binary representation** of **-7** is **1000 0000 0000 0111**.
* Therefore, the correct answer is **1000 0000 0000 0111**.
#### 93. Convert the 1000 0000 0000 1111 signed binary number to decimal number
1. +15
2. -30
3. -15
4. +30
Show me the answer
**Answer:** 3. -15
**Explanation:**
* The **signed binary number** **1000 0000 0000 1111** represents **-15** in decimal.
* Therefore, the correct answer is **-15**.
#### 94. What is the 2's complement of 0011 0101 1001 1100 number?
1. -1100 1001 1100 1011
2. 1100 1010 0110 0100
3. 1100 1010 0110 0011
4. 1100 1010 1111 1111
Show me the answer
**Answer:** 2. 1100 1010 0110 0100
**Explanation:**
* The **2's complement** of **0011 0101 1001 1100** is **1100 1010 0110 0100**.
* Therefore, the correct answer is **1100 1010 0110 0100**.
#### 95. What is the 2's-complement presentation of -24 in a 16-bit microcomputer?
1. 0000 0000 0001 1000
2. 1111 1111 1110 1000
3. 1111 1111 1110 0111
4. 0001 0001 1111 0011
Show me the answer
**Answer:** 2. 1111 1111 1110 1000
**Explanation:**
* The **2's complement representation** of **-24** in a **16-bit microcomputer** is **1111 1111 1110 1000**.
* Therefore, the correct answer is **1111 1111 1110 1000**.
#### 96. A flip-flop is a ...element that stores a binary digit as a low or high voltage
1. Chip
2. I/O
3. Bus
4. Memory
Show me the answer
**Answer:** 4. Memory
**Explanation:**
* A **flip-flop** is a **memory element** that stores a binary digit as a low or high voltage.
* Therefore, the correct answer is **Memory**.
#### 97. 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
1. No change, set
2. High, reset
3. Race, high
4. Set. Reset
Show me the answer
**Answer:** 2. High, reset
**Explanation:**
* In an **RS latch**, a **high S** and **low R** sets the output to **HIGH**, and a **low S** and **high R** resets the output to **LOW**.
* Therefore, the correct answer is **High, reset**.
#### 98. With a NAND latch a low R and a low S produce a:.....condition
1. Race
2. Reset
3. Set
4. No change
Show me the answer
**Answer:** 1. Race
**Explanation:**
* In a **NAND latch**, a **low R** and **low S** produce a **race condition**.
* Therefore, the correct answer is **Race**.
#### 99. Computers use thousands of flip-flops. To coordinate the overall action, a common signal called the ...is sent to each flip-flop
1. Latch
2. Master
3. Clock
4. Slave
Show me the answer
**Answer:** 3. Clock
**Explanation:**
* A **clock signal** is used to coordinate the overall action of flip-flops in a computer.
* Therefore, the correct answer is **Clock**.
#### 100. With positive clocking the clock signal must be.....for the flip-flop to respond
1. High
2. Set
3. Low
4. Race
Show me the answer
**Answer:** 1. High
**Explanation:**
* With **positive clocking**, the clock signal must be **HIGH** for the flip-flop to respond.
* Therefore, the correct answer is **High**.