Engineering Questions with Answers - Multiple Choice Questions

MCQs on Instruction Set Features -1

1 - Question

In which of these modes, the immediate operand is included in the instruction itself?
a) register operand mode
b) immediate operand mode
c) register and immediate operand mode
d) none of the mentioned

View Answer

Answer: b
Explanation: In immediate operand mode, the immediate operand is included in the instruction itself.




2 - Question

In register address mode, the operand is stored in
a) 8-bit general purpose register
b) 16-bit general purpose register
c) si or di
d) all of the mentioned

View Answer

Answer: d
Explanation: In register address mode, the operand is stored either in one of the 8-bit or 16-bit general purpose registers or in SI, DI, BX or BP.




3 - Question

In which of the following addressing mode, the offset is obtained by adding displacement and contents of one of the base registers?
a) direct mode
b) register mode
c) based mode
d) indexed mode

View Answer

Answer: c
Explanation: In a based mode, the offset is obtained by adding displacement and contents of one of the base registers, either BX or BP.




4 - Question

In which of the following addressing mode, the offset is obtained by adding displacement, with the contents of SI?
a) direct mode
b) register mode
c) based mode
d) indexed mode

View Answer

Answer: d
Explanation: In an indexed mode, the offset is obtained by adding displacement, with contents of an index register, either SI or DI.




5 - Question

The address of a location of the operand is calculated by adding the contents of any of the base registers, with the contents of any of index registers in
a) based indexed mode with displacement
b) based indexed mode
c) based mode
d) indexed mode

View Answer

Answer: b
Explanation: In a based indexed mode, the operand is stored at a location, whose address is calculated by adding the contents of any of the base registers, with the contents of any of the index registers.




6 - Question

Which of the following is not a data type of 80286?
a) Ordinal or unsigned
b) ASCII
c) Packed BCD
d) None of the mentioned

View Answer

Answer: d
Explanation: The 80286 supports seven data types. They are
1. integer
2. Ordinal (unsigned)
3. pointer
4. string
5. ASCII
6. BCD
7. Packed BCD.




7 - Question

The representation of 8-bit or 16-bit signed binary operands using 2’s complement is a data type of
a) Ordinal
b) ASCII
c) Packed BCD
d) integer

View Answer

Answer: d
Explanation: In integer data type, 8-bit or 16-bit signed binary operands are represented using 2’s complement.




8 - Question

The instruction that pushes the general purpose registers, pointer and index registers on to the stack is
a) POPF
b) PUSH Imd
c) PUSH*A
d) PUSHF

View Answer

Answer: c
Explanation: The PUSH*A instruction, pushes the general purpose registers, AX, CX, DX and BX, pointer and index registers, SP, BP, SI, DI, on to the stack.




9 - Question

While executing the PUSH*A instruction, the stack pointer is decremented by
a) 1 bit
b) 2 bits
c) 4 bits
d) 16 bits

View Answer

Answer: b
Explanation: The stack pointer is decremented by 16 (eight 2-byte registers).




10 - Question

The statement that is true for the instruction POP*A is
a) flags are unaffected
b) no operands are required
c) exceptions generated are same as that of PUSH*A
d) all of the mentioned

View Answer

Answer: d
Explanation: The POP*A instruction, pops all the contents of the registers DI, SI, BP, SP, BX, DX, CX and AX from the stack in this sequence, that is exactly opposite to that of pushing.




11 - Question

The instruction that multiplies the content of AL with a signed immediate operand is
a) MUL
b) SMUL
c) IMUL
d) None of the mentioned

View Answer

Answer: c
Explanation: The IMUL instruction multiplies the content of AL with a signed immediate operand, and the signed 16-bit result is stored in AX.




12 - Question

The instruction that represents the ‘rotate source, count’ is
a) RCL
b) RCR
c) ROR
d) All of the mentioned

View Answer

Answer: d
Explanation: The rotate source, count is a group of four instructions containing RCL, RCR, ROL, ROR.

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