WGU D686 – Operating Systems for Computer Scientists | Objective Assessment
| OA V1 and V2 | Questions and Answers | 2026 Update | 100% Correct.
SECTION 1: OS Fundamentals (1–10)
1. What is the primary role of an operating system?
A. Compile programs
B. Manage hardware and provide services to applications
C. Execute Java bytecode
D. Provide internet access
Answer: B
Explanation: The OS manages CPU, memory, storage, I/O, and provides system calls.
2. Which component handles CPU allocation?
A. Memory manager
B. File system
C. Scheduler
D. Shell
Answer: C
3. A system call is used to:
A. Access kernel services
B. Modify BIOS
C. Overclock CPU
D. Edit registry
,Answer: A
4. User mode differs from kernel mode because it:
A. Has full hardware access
B. Has restricted privileges
C. Is faster
D. Uses no memory
Answer: B
5. Which OS structure layers services hierarchically?
A. Monolithic
B. Microkernel
C. Layered
D. Exokernel
Answer: C
6. A microkernel design moves which services to user space?
A. CPU scheduling
B. Device drivers and file systems
C. Interrupt handling
D. Paging hardware
Answer: B
,7. The shell primarily:
A. Schedules processes
B. Manages memory
C. Interfaces between user and OS
D. Encrypts files
Answer: C
8. Which interrupt is software-generated?
A. Timer interrupt
B. I/O interrupt
C. Trap
D. Power interrupt
Answer: C
9. Multiprogramming improves:
A. Security
B. CPU utilization
C. Power consumption
D. Disk speed
Answer: B
, 10. Context switching saves and restores:
A. Disk sectors
B. Process state
C. Cache lines
D. File descriptors
Answer: B
SECTION 2: Processes & Threads (11–25)
11. A process consists of:
A. Only code
B. Code, data, stack, heap, PCB
C. Kernel only
D. RAM only
Answer: B
12. PCB stands for:
A. Process Control Block
B. Program Cache Buffer
C. Processor Cache Block
D. Parallel Control Bus
Answer: A
| OA V1 and V2 | Questions and Answers | 2026 Update | 100% Correct.
SECTION 1: OS Fundamentals (1–10)
1. What is the primary role of an operating system?
A. Compile programs
B. Manage hardware and provide services to applications
C. Execute Java bytecode
D. Provide internet access
Answer: B
Explanation: The OS manages CPU, memory, storage, I/O, and provides system calls.
2. Which component handles CPU allocation?
A. Memory manager
B. File system
C. Scheduler
D. Shell
Answer: C
3. A system call is used to:
A. Access kernel services
B. Modify BIOS
C. Overclock CPU
D. Edit registry
,Answer: A
4. User mode differs from kernel mode because it:
A. Has full hardware access
B. Has restricted privileges
C. Is faster
D. Uses no memory
Answer: B
5. Which OS structure layers services hierarchically?
A. Monolithic
B. Microkernel
C. Layered
D. Exokernel
Answer: C
6. A microkernel design moves which services to user space?
A. CPU scheduling
B. Device drivers and file systems
C. Interrupt handling
D. Paging hardware
Answer: B
,7. The shell primarily:
A. Schedules processes
B. Manages memory
C. Interfaces between user and OS
D. Encrypts files
Answer: C
8. Which interrupt is software-generated?
A. Timer interrupt
B. I/O interrupt
C. Trap
D. Power interrupt
Answer: C
9. Multiprogramming improves:
A. Security
B. CPU utilization
C. Power consumption
D. Disk speed
Answer: B
, 10. Context switching saves and restores:
A. Disk sectors
B. Process state
C. Cache lines
D. File descriptors
Answer: B
SECTION 2: Processes & Threads (11–25)
11. A process consists of:
A. Only code
B. Code, data, stack, heap, PCB
C. Kernel only
D. RAM only
Answer: B
12. PCB stands for:
A. Process Control Block
B. Program Cache Buffer
C. Processor Cache Block
D. Parallel Control Bus
Answer: A
