CS401 Quiz 1 Set 2

Q1. Whenever we need access to a memory location whose address is not known until run-time we use _________.

1. Index Register
2. Destination Register
3. Accumulator Register
4. Counter Register

Correct answer: Index Register

Q2. Which of the following is the most illegal instruction?

1. Mov ax, [num1]
2. Mov al, ax
3. Mov ax, al
4. Mov al, [num1]

Correct answer: Mov al, ax

Q3. A symbol associated to a point in the program is called a ___________.

1. Stack
2. Subroutines
3. JUMP
4. Label

Correct answer: Label

Q4. To modify the processor's behavior, ________________ instructions are used.

1. program control
2. data movement
3. arithmetic logic
4. special

Correct answer: special

Q5. The _______________ flag has a special role in debugging.

1. trap
2. parity
3. sign
4. zero

Correct answer: trap

Q6. The ________ flag sets if the last mathematical or logical instruction has produced a zero in its destination.

1. Trap
2. Interrupt
3. Zero
4. Sign

Correct answer: Zero

Q7. In ______________, a zero is inserted from the right and every bit moves one position to its left with the most significant bit dropped into the carry flag.

1. SAL
2. SAR
3. SHL
4. both SHL and SAL

Correct answer: both SHL and SAL

Q8. Which of the following register is used to hold address of the next instruction to be executed?

1. Program Counter
2. Index register
3. Counter register
4. Accumulator register

Correct answer: Program Counter

Q9. What is the purpose of MOV AX, 0xFFFF?

1. Add 0xFFFF into AX
2. Copy 0xFFFE into AX
3. Move AX into 0xFFFF
4. Store 0xFFFF into AX

Correct answer: Store 0xFFFF into AX

Q10. By default, IP is associated with __________________.

1. CX
2. BP
3. CS
4. SS

Correct answer: CS