Computer Architecture & Assembly Language MCQs with Answers
Practice important Computer Architecture & Assembly Language MCQs with answers and explanations.
Chapter: 13
Q281:
Which INT 21h service is used to delete a file?
A. 3Ch
B. 3Dh
C. 41h
D. 42h
Correct Answer:
C
Chapter: 13
Q282:
What is stored in the first 446 bytes of a hard disk’s physical sector 0?
A. Partition table
B. Master Boot Record (MBR)
C. FAT32 LBA
D. NTFS
Correct Answer:
B
Chapter: 13
Q283:
What does the INT 21h - READ FROM FILE service return?
A. File size
B. Number of bytes read
C. Error code
D. File handle
Correct Answer:
B
Chapter: 13
Q284:
Which of the following describes the command tail in the program segment prefix?
A. Information for BIOS
B. Actual command tail
C. Command tail length
D. Program code
Correct Answer:
B
Chapter: 13
Q285:
What does the INT 21h - SET CURRENT FILE POSITION service do?
A. Set file attributes
B. Move file pointer
C. Create a new file
D. Delete a file
Correct Answer:
B
Chapter: 13
Q286:
In the example code, what does the instruction mov ah, 2 followed by int 0x13 do?
A. Resets disk system
B. Reads sectors into memory
C. Writes sectors to disk
D. Gets drive parameters
Correct Answer:
B
Chapter: 13
Q287:
What is the logical structure built by DOS on raw storage space used for?
A. To directly manage hardware
B. To provide abstractions like files and directories
C. To read BIOS settings
D. To rotate the disk
Correct Answer:
B
Chapter: 13
Q288:
What does the rep movsb instruction in the provided code do?
A. Reads from disk
B. Writes to disk
C. Copies a string of bytes
D. Terminates the program
Correct Answer:
C
Chapter: 13
Q289:
What is the primary purpose of the INT 13h - GET DRIVE PARAMETERS service?
A. To get drive parameters
B. To reset disk system
C. To read sectors into memory
D. To write sectors to disk
Correct Answer:
A
Chapter: 13
Q290:
Which DOS service is used to truncate a file?
A. INT 21h - CREATE OR TRUNCATE FILE
B. INT 21h - DELETE FILE
C. INT 21h - SET CURRENT FILE POSITION
D. INT 21h - GET FILE ATTRIBUTES
Correct Answer:
A
Chapter: 13
Q291:
In the context of the provided example code, what does the instruction jc error do?
A. Jump to next entry
B. Compare files
C. Jump if there is an error
D. Continue execution
Correct Answer:
C
Chapter: 13
Q292:
How many directory entries are reserved in the root directory on a standard floppy disk?
A. 128
B. 256
C. 512
D. 1024
Correct Answer:
C
Chapter: 13
Q293:
What is the size of a standard partition table entry?
A. 10 bytes
B. 16 bytes
C. 32 bytes
D. 64 bytes
Correct Answer:
B
Chapter: 13
Q294:
What is the function of the INT 21h - WRITE TO FILE service?
A. Read from a file
B. Write to a file
C. Delete a file
D. Close a file
Correct Answer:
B
Chapter: 13
Q295:
What is the role of the int 0x21 instruction in the provided example code?
A. Calls BIOS services
B. Calls DOS services
C. Reads from memory
D. Writes to memory
Correct Answer:
B
Chapter: 13
Q296:
What DOS interrupt is used to allocate memory?
A. INT 21h
B. INT 20h
C. INT 22h
D. INT 23h
Correct Answer:
A
Chapter: 13
Q297:
Which register is used to specify the number of paragraphs to allocate in memory with INT 21h, AH=48h?
A. AX
B. BX
C. CX
D. DX
Correct Answer:
B
Chapter: 13
Q298:
What does INT 21h, AH=49h service do?
A. Allocate Memory
B. Free Memory
C. Resize Memory
D. Load and Execute Program
Correct Answer:
B
Chapter: 13
Q299:
In the file comparison program, what service is used to open a file?
A. INT 21h, AH=3Ch
B. INT 21h, AH=3Dh
C. INT 21h, AH=3Eh
D. INT 21h, AH=3Fh
Correct Answer:
B
Chapter: 13
Q300:
What is the role of the repne scasb instruction in the file comparison program?
A. Search for a space
B. Search for a null character
C. Search for a specified byte
D. Search for a digit
Correct Answer:
A