> 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-microprocessor/set-3.md).
# set-3
### 1. A microprocessor is a \_\_\_\_\_\_ chip integrating all the functions of a CPU of a computer.
1. Multiple
2. Single
3. Double
4. Triple
Show me the answer
**Answer:** 2. Single
**Explanation:**
* A microprocessor is a single integrated circuit (IC) that contains the central processing unit (CPU) of a computer. It integrates all the functions of a CPU, including arithmetic logic unit (ALU), control unit, and registers, into one chip.
### 2. Microprocessor is a/a\_\_\_\_\_\_ circuit that functions as the CPU of the computer.
1. Electronic
2. Mechanic
3. Integrating
4. Processing
Show me the answer
**Answer:** 1. Electronic
**Explanation:**
* A microprocessor is an electronic circuit that functions as the CPU of a computer. It is made up of millions of transistors and other components that work together to execute instructions and perform calculations.
### 3. Microprocessor is the \_\_\_\_\_\_ of the computer and it performs all the computational tasks.
1. Main
2. Heart
3. Important
4. Simple
Show me the answer
**Answer:** 2. Heart
**Explanation:**
* The microprocessor is often referred to as the "heart" of the computer because it performs all the computational tasks and controls the operation of the computer. It executes instructions from programs and manages data processing.
### 4. The purpose of the microprocessor is to control \_\_\_\_\_\_.
1. Memory
2. Switches
3. Processing
4. Tasks
Show me the answer
**Answer:** 3. Processing
**Explanation:**
* The primary purpose of a microprocessor is to control the processing of data. It executes instructions from programs, performs arithmetic and logical operations, and manages the flow of data between different components of the computer.
### 5. The first digital electronic computer was built in the year \_\_\_\_\_\_.
1. 1950
2. 1960
3. 1940
4. 1930
Show me the answer
**Answer:** 3. 1940
**Explanation:**
* The first digital electronic computer, known as the Atanasoff-Berry Computer (ABC), was built in 1940 by John Vincent Atanasoff and Clifford Berry. It was designed to solve systems of linear equations and is considered one of the earliest examples of a digital computer.
### 6. In 1960's Texas Instruments invented \_\_\_\_\_\_.
1. Integrated circuits
2. Vacuum tubes
3. Microprocessor
4. Transistors
Show me the answer
**Answer:** 1. Integrated circuits
**Explanation:**
* In the 1960s, Texas Instruments (TI) played a significant role in the invention and development of integrated circuits (ICs). Jack Kilby of TI is credited with creating the first working integrated circuit in 1958, which revolutionized electronics and paved the way for modern microprocessors.
### 7. The Intel 8086 microprocessor is a \_\_\_\_\_\_ processor.
1. 8-bit
2. 16-bit
3. 32-bit
4. 4-bit
Show me the answer
**Answer:** 2. 16-bit
**Explanation:**
* The Intel 8086 is a 16-bit microprocessor, meaning it can process 16 bits of data at a time. It was introduced in 1978 and became the foundation of the x86 architecture, which is still used in many modern computers.
### 8. The microprocessor can read/write 16-bit data from or to \_\_\_\_\_\_.
1. Memory
2. I/O device
3. Processor
4. Register
Show me the answer
**Answer:** 1. Memory
**Explanation:**
* The microprocessor can read and write 16-bit data from or to memory. This means it can transfer 16 bits of data between the CPU and the memory in a single operation, which is a key feature of 16-bit processors like the Intel 8086.
### 9. In 8086 microprocessors, the address bus is \_\_\_\_\_\_ bit wide.
1. 12-bit
2. 10-bit
3. 16-bit
4. 20-bit
Show me the answer
**Answer:** 4. 20-bit
**Explanation:**
* The Intel 8086 microprocessor has a 20-bit address bus, which allows it to address up to $$2^{20}$$ (1,048,576) memory locations, or 1 MB of memory. This was a significant improvement over earlier 8-bit processors.
### 10. The work of EU is \_\_\_\_\_\_.
1. Encoding
2. Decoding
3. Processing
4. Calculations
Show me the answer
**Answer:** 2. Decoding
**Explanation:**
* The Execution Unit (EU) in a microprocessor is responsible for decoding instructions and executing them. It fetches instructions from memory, decodes them, and then performs the necessary operations, such as arithmetic or logical calculations.
### 11. The 16-bit flag of 8086 microprocessor is responsible to indicate \_\_\_\_\_\_.
1. The condition of the result of ALU operation
2. Condition of memory
3. The result of addition
4. The result of subtraction
Show me the answer
**Answer:** 1. The condition of the result of ALU operation
**Explanation:**
* The 16-bit flag register in the 8086 microprocessor is used to indicate the status of the result of arithmetic and logical operations performed by the Arithmetic Logic Unit (ALU). Flags such as Carry Flag (CF), Zero Flag (ZF), and Sign Flag (SF) provide information about the outcome of operations.
### 12. The CF is known as \_\_\_\_\_\_.
1. Carry flag
2. Condition flag
3. Common flag
4. Single flag
Show me the answer
**Answer:** 1. Carry flag
**Explanation:**
* The Carry Flag (CF) is a status flag in the 8086 microprocessor that indicates whether an arithmetic operation has generated a carry or borrow out of the most significant bit (MSB). It is set to 1 if there is a carry or borrow, otherwise, it is set to 0.
### 13. The SF is called as \_\_\_\_\_\_.
1. Service flag
2. Sign flag
3. Single flag
4. Condition flag
Show me the answer
**Answer:** 2. Sign flag
**Explanation:**
* The Sign Flag (SF) is a status flag in the 8086 microprocessor that indicates the sign of the result of an arithmetic operation. If the result is negative, the SF is set to 1; if the result is positive, the SF is set to 0.
### 14. The OF is called as \_\_\_\_\_\_.
1. Overflow flag
2. Overdue flag
3. One flag
4. Overflag
Show me the answer
**Answer:** 1. Overflow flag
**Explanation:**
* The Overflow Flag (OF) is a status flag in the 8086 microprocessor that indicates whether an arithmetic operation has resulted in an overflow. An overflow occurs when the result of an operation is too large to be represented in the destination operand.
### 15. The IF is called as \_\_\_\_\_\_.
1. Initial flag
2. Indicate flag
3. Interrupt flag
4. Enter flag
Show me the answer
**Answer:** 3. Interrupt flag
**Explanation:**
* The Interrupt Flag (IF) is a control flag in the 8086 microprocessor that determines whether the processor will respond to maskable hardware interrupts. If the IF is set to 1, the processor will accept interrupts; if it is set to 0, interrupts will be ignored.
### 16. The register AX is formed by grouping\_\_\_\_\_\_.
1. AH & AL
2. BH & BL
3. CH & CL
4. DH & DL
Show me the answer
**Answer:** 1. AH & AL
**Explanation:**
* The AX register in the 8086 microprocessor is a 16-bit register that is formed by grouping two 8-bit registers: AH (high byte) and AL (low byte). AX is commonly used for arithmetic operations and data manipulation.
### 17. The SP is indicated by\_\_\_\_\_\_.
1. Single pointer
2. Source pointer
3. Stack pointer
4. Destination pointer
Show me the answer
**Answer:** 3. Stack pointer
**Explanation:**
* The Stack Pointer (SP) is a 16-bit register in the 8086 microprocessor that points to the top of the stack. The stack is a region of memory used for temporary storage of data, and the SP is used to manage the stack during function calls and interrupts.
### 18. The BP is indicated by\_\_\_\_\_\_.
1. Base pointer
2. Binary pointer
3. Bit pointer
4. Digital pointer
Show me the answer
**Answer:** 1. Base pointer
**Explanation:**
* The Base Pointer (BP) is a 16-bit register in the 8086 microprocessor that is used to point to the base of the stack frame. It is often used in conjunction with the Stack Pointer (SP) to access local variables and parameters within a function.
### 19. The SS is called as\_\_\_\_\_\_.
1. Single stack
2. Stack segment
3. Sequence stack
4. Random stack
Show me the answer
**Answer:** 2. Stack segment
**Explanation:**
* The Stack Segment (SS) is a segment register in the 8086 microprocessor that holds the base address of the stack segment. The stack segment is a region of memory used for storing temporary data, such as function return addresses and local variables.
### 20. The index register is used to hold\_\_\_\_\_\_.
1. Memory register
2. Segment memory
3. Offset address
4. Offset memory
Show me the answer
**Answer:** 3. Offset address
**Explanation:**
* The index registers (SI and DI) in the 8086 microprocessor are used to hold offset addresses. These registers are often used in string operations and memory addressing modes to point to specific locations in memory.
### 21. The BIU contains FIFO register of size\_\_\_\_\_\_ bytes.
1. 8
2. 6
3. 4
4. 12
Show me the answer
**Answer:** 2. 6
**Explanation:**
* The Bus Interface Unit (BIU) in the 8086 microprocessor contains a First-In-First-Out (FIFO) register of size 6 bytes. This FIFO register is used to prefetch instructions from memory, allowing the CPU to execute instructions more efficiently by reducing wait times.
### 22. The BIU prefetches the instruction from memory and stores them in\_\_\_\_\_\_.
1. Queue
2. Register
3. Memory
4. Stack
Show me the answer
**Answer:** 1. Queue
**Explanation:**
* The BIU prefetches instructions from memory and stores them in a queue. This prefetching mechanism allows the CPU to have a steady stream of instructions ready for execution, improving overall performance by reducing idle time.
### 23. The 1 MB byte of memory can be divided into\_\_\_\_\_\_ segments.
1. 1 Kbyte
2. 64 Kbyte
3. 33 Kbyte
4. 34 Kbyte
Show me the answer
**Answer:** 2. 64 Kbyte
**Explanation:**
* The 8086 microprocessor uses a segmented memory model, where the 1 MB of addressable memory is divided into segments of 64 KB each. This allows the processor to address a larger memory space using 16-bit segment registers.
### 24. The DS is called as\_\_\_\_\_\_.
1. Data segment
2. Divide segment
3. Digital segment
4. Decode segment
Show me the answer
**Answer:** 1. Data segment
**Explanation:**
* The Data Segment (DS) is a segment register in the 8086 microprocessor that holds the base address of the data segment. The data segment is used for storing data that the program operates on.
### 25. The CS register stores instruction in code segment.
1. Stream
2. Path
3. Codes
4. Streamline
Show me the answer
**Answer:** 3. Codes
**Explanation:**
* The Code Segment (CS) register in the 8086 microprocessor holds the base address of the code segment. The code segment contains the instructions that the CPU executes.
### 26. The IP is\_\_\_\_\_\_ bits in length.
1. 8 bits
2. 4 bits
3. 16 bits
4. 32 bits
Show me the answer
**Answer:** 3. 16 bits
**Explanation:**
* The Instruction Pointer (IP) is a 16-bit register in the 8086 microprocessor that holds the offset address of the next instruction to be executed within the code segment.
### 27. The push source copies a word from source to\_\_\_\_\_\_.
1. Stack
2. Memory
3. Register
4. Destination
Show me the answer
**Answer:** 1. Stack
**Explanation:**
* The PUSH instruction in the 8086 microprocessor copies a word (16 bits) from the source (register or memory) to the stack. The stack is a Last-In-First-Out (LIFO) data structure used for temporary storage.
### 28. LDs copies to consecutive words from memory to register and\_\_\_\_\_\_.
1. ES
2. DS
3. SS
4. CS
Show me the answer
**Answer:** 2. DS
**Explanation:**
* The LDS (Load Data Segment) instruction in the 8086 microprocessor loads a far pointer (32 bits) from memory into a specified register and the DS (Data Segment) register. The far pointer consists of a 16-bit offset and a 16-bit segment address.
### 29. INC destination increments the content of destination by\_\_\_\_\_\_.
1. 1
2. 20
3. 2
4. 41
Show me the answer
**Answer:** 1. 1
**Explanation:**
* The INC (Increment) instruction in the 8086 microprocessor increments the content of the destination operand (register or memory location) by 1. It is commonly used in loops and counters.
### 30. IMUL source is assigned\_\_\_\_\_\_.
1. Multiplication
2. Subtraction
3. Addition
4. Division
Show me the answer
**Answer:** 1. Multiplication
**Explanation:**
* The IMUL (Integer Multiply) instruction in the 8086 microprocessor performs signed multiplication of the source operand with the accumulator (AX or AL) and stores the result in the accumulator.
### 31. \_\_\_\_\_\_ destination inverts each bit of destination.
1. NOT
2. NOR
3. AND
4. OR
Show me the answer
**Answer:** 1. NOT
**Explanation:**
* The NOT instruction in the 8086 microprocessor performs a bitwise inversion of the destination operand. Each bit in the destination is flipped (0 becomes 1 and 1 becomes 0).
### 32. The JS is called as\_\_\_\_\_\_.
1. Jump the signed bit
2. Jump simplicit
3. Jump single bit
4. Jump signalit
Show me the answer
**Answer:** 1. Jump the signed bit
**Explanation:**
* The JS (Jump if Sign) instruction in the 8086 microprocessor is a conditional jump instruction that transfers control to a target address if the Sign Flag (SF) is set to 1, indicating a negative result from a previous arithmetic operation.
### 33. Instruction providing both segment base and offset address are called\_\_\_\_\_\_.
1. Below type
2. Far type
3. Low type
4. High type
Show me the answer
**Answer:** 2. Far type
**Explanation:**
* Far instructions in the 8086 microprocessor provide both the segment base and offset address. These instructions are used to access memory locations outside the current segment, allowing the processor to address the full 1 MB memory space.
### 34. The conditional branch instruction specifies\_\_\_\_\_\_ for branching.
1. Conditions
2. Instruction
3. Address
4. Memory
Show me the answer
**Answer:** 1. Conditions
**Explanation:**
* Conditional branch instructions in the 8086 microprocessor specify conditions for branching based on the status of flags in the flag register. For example, the JZ (Jump if Zero) instruction branches if the Zero Flag (ZF) is set to 1.
### 35. The microprocessor determines whether the specified condition exists or not by testing the\_\_\_\_\_\_.
1. Common
2. Carry flag
3. Conditional flag
4. Sign flag
Show me the answer
**Answer:** 3. Conditional flag
**Explanation:**
* The microprocessor determines whether a specified condition exists by testing the appropriate conditional flag in the flag register. For example, the Zero Flag (ZF) is tested for zero conditions, and the Carry Flag (CF) is tested for carry conditions.
### 36. The LES copies to words from memory to register and\_\_\_\_\_\_.
1. DS
2. CS
3. ES
4. DS
Show me the answer
**Answer:** 3. ES
**Explanation:**
* The LES (Load Extra Segment) instruction in the 8086 microprocessor loads a far pointer (32 bits) from memory into a specified register and the ES (Extra Segment) register. The far pointer consists of a 16-bit offset and a 16-bit segment address.
### 37. The \_\_\_\_\_\_ translates a byte from one code to another code.
1. XLAT
2. XCHNG
3. POP
4. PUSH
Show me the answer
**Answer:** 1. XLAT
**Explanation:**
* The XLAT (Translate) instruction in the 8086 microprocessor is used to translate a byte from one code to another using a translation table. The AL register is used as an index into the table, and the translated byte is stored back in AL.
### 38. The \_\_\_\_\_\_ contains an offset instead of an actual address.
1. SP
2. IP
3. ES
4. SS
Show me the answer
**Answer:** 2. IP
**Explanation:**
* The Instruction Pointer (IP) in the 8086 microprocessor contains an offset address within the current code segment. The actual memory address is calculated by combining the segment base address (CS) with the offset (IP).
### 39. The 8086 fetches instruction one after another from \_\_\_\_\_\_ of memory.
1. Code segment
2. ES
3. IP
4. SS
Show me the answer
**Answer:** 1. Code segment
**Explanation:**
* The 8086 microprocessor fetches instructions sequentially from the code segment (CS) of memory. The Instruction Pointer (IP) holds the offset address within the code segment, and the actual address is calculated as $$CS \times 16 + IP$$.
### 40. The BIU contains FIFO register of size 6 bytes called \_\_\_\_\_\_.
1. Queue
2. Stack
3. Segment
4. Register
Show me the answer
**Answer:** 1. Queue
**Explanation:**
* The Bus Interface Unit (BIU) in the 8086 microprocessor contains a First-In-First-Out (FIFO) register of size 6 bytes, which is referred to as a queue. This queue is used to prefetch instructions from memory, improving the efficiency of instruction execution.
### 41. The \_\_\_\_\_\_ is required to synchronize the internal operands in the processor CLK Signal.
1. UR Signal
2. Vec
3. AIE
4. Ground
Show me the answer
**Answer:** 1. UR Signal
**Explanation:**
* The UR (Update Register) signal is used to synchronize the internal operands in the processor with the clock (CLK) signal. This ensures that data is processed correctly and in sync with the processor's clock cycles.
### 42. The pin of minimum mode AD0-AD15 has \_\_\_\_\_\_ address.
1. 16-bit
2. 20-bit
3. 32-bit
4. 4-bit
Show me the answer
**Answer:** 2. 20-bit
**Explanation:**
* In minimum mode, the AD0-AD15 pins of the 8086 microprocessor are multiplexed to carry both address and data. The address bus is 20 bits wide, allowing the processor to address up to 1 MB of memory.
### 43. The pin of minimum mode AD0-AD15 has \_\_\_\_\_\_ data bus.
1. 4-bit
2. 20-bit
3. 16-bit
4. 32-bit
Show me the answer
**Answer:** 3. 16-bit
**Explanation:**
* In minimum mode, the AD0-AD15 pins of the 8086 microprocessor are used as a 16-bit data bus. These pins are multiplexed to carry both address and data, but during data transfer, they function as a 16-bit data bus.
### 44. The address bits are sent out on lines through \_\_\_\_\_\_.
1. 16-19
2. A0-17
3. D0-D17
4. C0-C17
Show me the answer
**Answer:** 1. 16-19
**Explanation:**
* The address bits in the 8086 microprocessor are sent out on lines A16-A19. These lines, along with AD0-AD15, form the 20-bit address bus, allowing the processor to address up to 1 MB of memory.
### 45. \_\_\_\_\_\_ is used to write into memory.
1. RD
2. WR
3. RD/WR
4. CLK
Show me the answer
**Answer:** 2. WR
**Explanation:**
* The WR (Write) signal in the 8086 microprocessor is used to indicate a write operation to memory or I/O devices. When WR is active, data is written from the processor to the specified memory or I/O location.
### 46. The functions of Pins from 24 to 31 depend on the mode in which \_\_\_\_\_\_ is operating.
1. 8085A
2. 80835
3. 8086
4. 80845
Show me the answer
**Answer:** 3. 8086
**Explanation:**
* The functions of pins 24 to 31 in the 8086 microprocessor depend on whether the processor is operating in minimum or maximum mode. In minimum mode, these pins are used for control signals, while in maximum mode, they are used for status signals.
### 47. The RD, WR, M/IO is the heart of control for a \_\_\_\_\_\_ mode.
1. Minimum
2. Compatibility mode
3. Maximum
4. Control mode
Show me the answer
**Answer:** 1. Minimum
**Explanation:**
* The RD (Read), WR (Write), and M/IO (Memory/Input-Output) signals are the primary control signals in minimum mode operation of the 8086 microprocessor. These signals control the flow of data between the processor and memory or I/O devices.
### 48. In a minimum mode there is a \_\_\_\_\_\_ on the system bus.
1. Single
2. Multiple
3. Double
4. Triple
Show me the answer
**Answer:** 1. Single
**Explanation:**
* In minimum mode, the 8086 microprocessor operates as a single processor on the system bus. All control signals are generated by the 8086 itself, and there is no external bus controller.
### 49. If MN/MX is low the 8086 operates in \_\_\_\_\_\_ mode.
1. Minimum
2. Both (A) and (B)
3. Maximum
4. Medium
Show me the answer
**Answer:** 3. Maximum
**Explanation:**
* The MN/MX (Minimum/Maximum) pin on the 8086 microprocessor determines the operating mode. If MN/MX is low, the processor operates in maximum mode, where control signals are generated by an external bus controller.
### 50. In max mode, control bus signal So, S1, and S2 are sent out in \_\_\_\_\_\_ form.
1. Decoded
2. Shared
3. Encoded
4. Unshared
Show me the answer
**Answer:** 3. Encoded
**Explanation:**
* In maximum mode, the control bus signals S0, S1, and S2 are sent out in encoded form. These signals are decoded by an external bus controller to generate the necessary control signals for memory and I/O operations.