In the name of ALLAH, the most beneficient, the most merciful

Computer Architecture and Assembly Language Programming (CS401)

Multiple Choice Questions (MCQs)

Objective Questions

  1. When an element is pushed on the stack SP is decremented by ________.

    1. 3
    2. 2
    3. 4
    4. 1
  2. The other directive is "define word" or "dw" with the same syntax as "db" but reserving a whole word of ________ bits instead of a byte.

    1. 32
    2. 8
    3. 16
    4. 64
  3. The 8088 processor divides interrupts into ________ classes.

    1. One
    2. Two
    3. Three
    4. Four
  4. Physical memory adresses is of

    1. 16 Bits
    2. 32 Bits
    3. 20 Bits
    4. 8 Bits
  5. Which of the following string instruction is generally used in a loop instead of REP prefix?

    1. SCAS
    2. LODS
    3. CMPS
    4. STOS
  6. "mov [bp], al" moves the one byte contents of the AL register to the address contained in BP register in the current ________.

    1. Stack Segment
    2. Data Segment
    3. Code Segment
    4. Extra Segment
  7. Number of operands of ADC (add with carry) register are:

    1. 1
    2. 2
    3. 3
    4. 4
  8. There are ________ registers in iAPX88 architecture that can hold address of data.

    1. 1
    2. 2
    3. 3
    4. 4
  9. In branching mechanism, the assembler

    1. Replaces the target with its address
    2. Does not replace until the test condition is satisfied
    3. Finds the Branch offset and replaces the Branch target with it
    4. Replaces the target with the value specified by the DATAWORD directive
  10. The purpose of MOVS instruction is:

    1. Move register to register
    2. Move register to a memory location
    3. Move a memory location to register
    4. Move memory to memory
  11. ASCII table is the contiguous arrangement of the upercase alphabets (41-5A), the lowercase alphabets (61-7A), and the numbers ________.

    1. 31-40
    2. 29-39
    3. 30-39
    4. 31-41
  12. In a comparison, if the both operands are same. The result of subtraction will be zero and the zero flag will be ________.

    1. Set
    2. Incremented
    3. Updated
    4. Decremented
  13. Which of the following is a non-destructive AND operation?

    1. AND
    2. XOR
    3. OR
    4. Test
  14. mov [1234], ax is an example of

    1. direct addressing
    2. base register indirect
    3. base+index addressing
    4. register indirect addressing
  15. DX plays an important role in arithmetic ________.

    1. addition
    2. multiplication
    3. division
    4. subtraction
  16. Which of the following Move generates error in .com file?

    1. Legal move
    2. Illegal move
    3. Ambiguous move
    4. Fetal move
  17. Which of the following register is used to hold address of the next instruction to be executed?

    1. Memory address register
    2. Memory data register
    3. Instruction registers
    4. Program counter
  18. ________ instruction makes the code reusable.

    1. Mov
    2. JMP
    3. CALL
    4. SHL
  19. How many characters were defined by standard ASCII?

    1. 132
    2. 124
    3. 122
    4. 128
  20. The top of stack is contained in ________ register.

    1. SP
    2. BP
    3. AX
    4. BX
  21. Sending the appropriate signals on the control bus to the memory is the responsibility of ________.

    1. Memory
    2. Processor
    3. Control Bus
    4. Data Bus
  22. The execution of the instruction "mov word [ES : 160], 0x1230" will print a character on the screen at:

    1. first column of second row
    2. second column of first row
    3. second column of second row
    4. first column of third row
  23. In ________ every bit moves one position to the right and the bit dropped from the right is inserted at the left and also copied into the carry flag?

    1. ROL
    2. RCR
    3. RCL
    4. ROR
  24. CX register is mostly used as a

    1. counter register
    2. flag register
    3. base register
    4. destination register
  25. If AX=5, BX=5, CF and ZF are set, AF and DX contains zero then after the execution of instruction "ADC AX, BX", AX will contain the value ________.

    1. 5
    2. 10
    3. 11
    4. 6
  26. MOV [BX+SI+300], AX is a ________ addressing mode instruction.

    1. Base + Index + Offset
    2. Base + Index
    3. Index Register Indirect + Offset
    4. Illegal
  27. In general, width of a memory cell cannot be greater than the width of ________.

    1. Control Bus
    2. Data Bus
    3. Address Bus
    4. I/O Bus
  28. All mathematical and logical operations are performed on the ________.

    1. Accumulator
    2. Arithmetic Logic Unit
    3. Program Counter
    4. Flag Register
  29. ________ is a special instruction that load a segment register and a general purpose register from a memory locations.

    1. SCAS
    2. MOV
    3. CALL
    4. LES
  30. Group of bits processor uses to inform memory which element to read/write is collectively known as

    1. Control bus
    2. Data bus
    3. Address bus
    4. RAM
  31. Which of the following operation is used to clear any specific bit in a binary number?

    1. AND
    2. OR
    3. XOR
    4. NOT
  32. Which part of this (00000000000 B80500) encoded instruction is an offset?

    1. First Column
    2. Second column
    3. B8
    4. 0500
  33. SCAS compares a source byte or word in register AL or AX with the ________ string element addressed by ES: DI and updates the flags.

    1. Source
    2. Destination
    3. Flag
    4. Register
  34. What does the given instruction do?
    SHR DL, 1

    1. move right most bit in carry
    2. move bit in DL
    3. Shift and store the One bit in DL
    4. Shift and store the most bit in DL
  35. ________ is set only when the last mathematical or logical operation produces a zero in its destination.

    1. Single Flag
    2. Zero flag
    3. Trap Flag
    4. Parity Flag
  36. The extention of assembly languague file is

    1. .doc
    2. .com
    3. .lst
    4. .asm
  37. Stack is a data structure that behaves in a first in last ________ manner.

    1. In
    2. Out
    3. Push
    4. Add
  38. The instruction, MOV AX, 0005H belongs to the address mode of ________ .

    1. Register
    2. Direct
    3. Immediate
    4. Register Relative
  39. This jump is taken if the last arithmethic operation produced a positive number in its destination.

    1. JNP
    2. JO
    3. JNS
    4. JG
  40. BH register is a ________ bit register.

    1. 8
    2. 16
    3. 24
    4. 32
  41. The jump command that does not depend on FLAG register is

    1. JCXZ
    2. JO
    3. JNE
    4. JP
  42. ________ is the basic means of sorting temporary data on the stack.

    1. PUSH
    2. POP
    3. CALL
    4. RET
  43. Which of the following addressing scheme has been used in the instruction MOV [BX], AX?

    1. Base Register Direct
    2. Base Register Indirect
    3. Base + Offset
    4. Base + Index
  44. ________ and ________ are taken if the last arithmetic operation produced a number in its destination that has odd parity.

    1. JP, JPE
    2. JS, JNS
    3. JCX, JNS
    4. JNP, JPO
  45. In case of 32-bit processor, the size of an accumulator register will be ________ bits.

    1. 16
    2. 8
    3. 32
    4. 64
  46. The interrupt call loads new values in ________ segment.

    1. ES
    2. DS
    3. CS
    4. SS
  47. The jump is taken if the last arithmetic operation changed the sign unexpectedly.

    1. JO
    2. JNO
    3. JNZ
    4. JZ
  48. All the addressing modes return the number after calculation, this number is known as ________ ?

    1. Base Address
    2. Offset Address
    3. Data Address
    4. Effective Address
  49. ________ is a temporary storage places inside the processor.

    1. Memory
    2. Ram
    3. Cache
    4. Register
  50. There are just ________ block processing instructions in 8088.

    1. 6
    2. 5
    3. 4
    4. 3
  51. MUL (multiply) instruction performs an unsigned multiplication of the source operand and the ________ .

    1. Accumulator
    2. Carry
    3. Word
    4. Base
  52. SP is associated with ____________ , by default.

    1. SS
    2. DS
    3. CS
    4. ES
  53. Which bit of the attributes byte represents the red component of foreground color?

    1. 5
    2. 4
    3. 3
    4. 2
  54. In STOSW instruction, when DF is clear, DI is ___________

    1. Incremented by 1
    2. Incremented by 2
    3. Decremented by 1
    4. Decremented by 2
  55. Which of the following interrupts is Non maskable interrupt?

    1. INT 2
    2. INT 3
    3. INT 0
    4. INT 1
  56. An 8 x 16 font is stored in ______________ bytes.

    1. 2
    2. 4
    3. 8
    4. 16
  57. In DOS input buffer, the number of characters actually read on return is stored in ___________ byte.

    1. 3rd
    2. 4th
    3. 1st
    4. 2nd
  58. Which of the following gives the more logical view of the storage medium?

    1. BIOS
    2. DOS
    3. Both
    4. None