Computer Architecture & Assembly Language MCQs with Answers
Practice important Computer Architecture & Assembly Language MCQs with answers and explanations.
Chapter: 15
Q341:
What is the maximum number of descriptors possible in the GDT?
A. 4096
B. 8192
C. 16384
D. 32768
Correct Answer:
B
Chapter: 15
Q342:
Which instruction loads the GDTR register?
A. LGDT
B. SGDT
C. LDTR
D. GDTR
Correct Answer:
A
Chapter: 15
Q343:
What must the first entry of the GDT always be?
A. A data descriptor
B. A code descriptor
C. A null descriptor
D. A stack descriptor
Correct Answer:
C
Chapter: 15
Q344:
What does the 'D' bit in a code descriptor indicate?
A. Data segment
B. Descriptor size
C. Debug mode
D. Default operation size
Correct Answer:
D
Chapter: 15
Q345:
What is the purpose of the P bit in a descriptor?
A. Page size
B. Program size
C. Segment presence
D. Processor mode
Correct Answer:
C
Chapter: 15
Q346:
Which segment selector is used to access the GDT?
A. TI=1
B. TI=0
C. RPL=1
D. RPL=0
Correct Answer:
B
Chapter: 15
Q347:
In the example code, what does the instruction mov byte [0x000b8000], 'A' do?
A. Sets up a memory segment
B. Prints 'A' on the screen
C. Moves 'A' to the stack
D. Changes segment selector
Correct Answer:
B
Chapter: 15
Q348:
Which interrupt is used to enable A20 in the provided examples?
A. INT 10h
B. INT 15h
C. INT 21h
D. INT 1Ah
Correct Answer:
B
Chapter: 15
Q349:
What does the VESA mode 4117 refer to?
A. 800x600 resolution with 16 colors
B. 1024x768 resolution with 16-bit color
C. 1280x1024 resolution with 24-bit color
D. 1920x1080 resolution with 32-bit color
Correct Answer:
B
Chapter: 15
Q350:
What is the color bit format for mode 4117?
A. 0.16949074074074
B. 0.21186342592593
C. 0.21255787037037
D. 0.25423611111111
Correct Answer:
C
Chapter: 15
Q351:
What is the size of each descriptor in the GDT?
A. 4 bytes
B. 6 bytes
C. 8 bytes
D. 10 bytes
Correct Answer:
C
Chapter: 15
Q352:
Which instruction is used to set the VESA video mode?
A. INT 10h, AX=4F00h
B. INT 10h, AX=4F01h
C. INT 10h, AX=4F02h
D. INT 10h, AX=4F03h
Correct Answer:
C
Chapter: 15
Q353:
In 32-bit mode, what does the instruction mov ds, ax accomplish?
A. Load the code segment
B. Load the stack segment
C. Load the data segment
D. Load the descriptor segment
Correct Answer:
C
Chapter: 15
Q354:
What is the purpose of the CLI instruction before switching to protected mode?
A. Enable interrupts
B. Disable interrupts
C. Clear memory
D. Set privilege level
Correct Answer:
B
Chapter: 15
Q355:
How is the base address of a segment descriptor filled in the provided examples?
A. Direct assignment
B. Using shifts and masking
C. By default
D. By interrupt
Correct Answer:
B
Chapter: 15
Q356:
In the printstr function, which register is used to point to the video base?
A. AX
B. BX
C. CX
D. ES
Correct Answer:
D
Chapter: 15
Q357:
What does the 'G' bit in a descriptor indicate?
A. Granularity (4K pages)
B. Global descriptor
C. Gate segment
D. General purpose
Correct Answer:
A
Chapter: 15
Q358:
What does the MUL instruction in the pprintstr function do?
A. Multiplies the string length by 2
B. Multiplies the Y offset
C. Multiplies the base address
D. Multiplies the descriptor index
Correct Answer:
B
Chapter: 16
Q359:
What is the term used for the behavior of a high-level language (HLL) when calling functions?
A. Function calling
B. Calling conventions
C. Calling protocols
D. Function directives
Correct Answer:
B
Chapter: 16
Q360:
In C calling conventions, in what order are parameters passed to the routine?
A. Left to right
B. Right to left
C. Random order
D. Sequential order
Correct Answer:
B