WGU C952
Part 1: Computer Abstractions and Technology (Questions 1-25)
1. In order for a program to run on a computer, it must be finally
expressed in _______.
A) an assembly language
B) a high-level language
C) an object-oriented language
D) a machine language
Answer: D) a machine language
Rationale: A program must be expressed in machine language (binary)
for the CPU to execute it directly. All higher-level languages (C++, Java)
are ultimately translated into machine code through compilers or
interpreters .
2. Which component of the CPU is responsible for performing
arithmetic and logical operations?
A) Control Unit
B) Register File
,C) Datapath
D) Program Counter
Answer: C) Datapath
Rationale: The datapath contains the Arithmetic Logic Unit (ALU) and
registers. The ALU performs the actual arithmetic (ADD, SUB) and logical
(AND, OR) operations. The Control Unit tells the datapath what to do,
but the datapath does the work .
3. What does CPI stand for, and what does it represent?
A) Code Performance Index; total instructions executed
B) Cycles Per Instruction; average clock cycles per executed instruction
C) Cache Priority Indicator; cache hit rate
D) Clock Period Interval; CPU voltage
Answer: B) Cycles Per Instruction; average clock cycles per executed
instruction
Rationale: CPI is a key performance metric. Lower CPI means better
performance. CPU Time = Instruction Count × CPI × Clock Cycle Time .
4. According to Amdahl's Law, the overall speedup of a system is
primarily limited by:
A) The clock speed of the processor
B) The amount of cache memory
C) The parallelizable fraction of the program
D) The number of I/O devices
,Answer: C) The parallelizable fraction of the program
Rationale: Amdahl's Law states that the speedup gained by improving a
part of a system is limited by how much that part is used. Specifically,
the serial (non-parallelizable) portion of a program creates a bottleneck
that cannot be overcome by improving other parts, even with infinite
resources .
5. What is the difference between gigabyte (GB) and gibibyte (GiB)?
A) GB is binary, GiB is decimal
B) GB is 10^9 bytes, GiB is 2^30 bytes
C) GB is used for RAM, GiB is used for storage
D) There is no difference; they are synonyms
Answer: B) GB is 10^9 bytes, GiB is 2^30 bytes
Rationale: This is a common point of confusion. Gigabyte (GB) follows
the decimal (SI) system (Base-10: 1,000,000,000 bytes). Gibibyte (GiB)
follows the binary system (Base-2: 1,073,741,824 bytes) used internally
by operating systems for memory addressing .
6. Which of the following is NOT one of the five classic components of
a computer?
A) Input
B) Output
C) Processor (datapath and control)
D) Firmware
E) Memory
, Answer: D) Firmware
Rationale: The five classic components of a computer are input, output,
memory, datapath, and control (the last two combined form the
processor). Firmware is a type of software stored in ROM, not a
hardware component .
7. Which memory type is volatile, fast, expensive, and used primarily
for cache?
A) DRAM
B) Flash
C) Magnetic Disk
D) SRAM
Answer: D) SRAM
Rationale: Static RAM (SRAM) uses flip-flops (transistors) to store bits. It
is faster and more expensive than DRAM, does not need refreshing, and
is used for L1, L2, and L3 caches. DRAM is used for main memory .
8. What is a "wafer" in semiconductor manufacturing?
A) The plastic package surrounding the CPU
B) The thin slice of silicon used to fabricate multiple chips
C) The metal heat spreader on top of the CPU
D) The conductive layer connecting transistors
Answer: B) The thin slice of silicon used to fabricate multiple chips
Part 1: Computer Abstractions and Technology (Questions 1-25)
1. In order for a program to run on a computer, it must be finally
expressed in _______.
A) an assembly language
B) a high-level language
C) an object-oriented language
D) a machine language
Answer: D) a machine language
Rationale: A program must be expressed in machine language (binary)
for the CPU to execute it directly. All higher-level languages (C++, Java)
are ultimately translated into machine code through compilers or
interpreters .
2. Which component of the CPU is responsible for performing
arithmetic and logical operations?
A) Control Unit
B) Register File
,C) Datapath
D) Program Counter
Answer: C) Datapath
Rationale: The datapath contains the Arithmetic Logic Unit (ALU) and
registers. The ALU performs the actual arithmetic (ADD, SUB) and logical
(AND, OR) operations. The Control Unit tells the datapath what to do,
but the datapath does the work .
3. What does CPI stand for, and what does it represent?
A) Code Performance Index; total instructions executed
B) Cycles Per Instruction; average clock cycles per executed instruction
C) Cache Priority Indicator; cache hit rate
D) Clock Period Interval; CPU voltage
Answer: B) Cycles Per Instruction; average clock cycles per executed
instruction
Rationale: CPI is a key performance metric. Lower CPI means better
performance. CPU Time = Instruction Count × CPI × Clock Cycle Time .
4. According to Amdahl's Law, the overall speedup of a system is
primarily limited by:
A) The clock speed of the processor
B) The amount of cache memory
C) The parallelizable fraction of the program
D) The number of I/O devices
,Answer: C) The parallelizable fraction of the program
Rationale: Amdahl's Law states that the speedup gained by improving a
part of a system is limited by how much that part is used. Specifically,
the serial (non-parallelizable) portion of a program creates a bottleneck
that cannot be overcome by improving other parts, even with infinite
resources .
5. What is the difference between gigabyte (GB) and gibibyte (GiB)?
A) GB is binary, GiB is decimal
B) GB is 10^9 bytes, GiB is 2^30 bytes
C) GB is used for RAM, GiB is used for storage
D) There is no difference; they are synonyms
Answer: B) GB is 10^9 bytes, GiB is 2^30 bytes
Rationale: This is a common point of confusion. Gigabyte (GB) follows
the decimal (SI) system (Base-10: 1,000,000,000 bytes). Gibibyte (GiB)
follows the binary system (Base-2: 1,073,741,824 bytes) used internally
by operating systems for memory addressing .
6. Which of the following is NOT one of the five classic components of
a computer?
A) Input
B) Output
C) Processor (datapath and control)
D) Firmware
E) Memory
, Answer: D) Firmware
Rationale: The five classic components of a computer are input, output,
memory, datapath, and control (the last two combined form the
processor). Firmware is a type of software stored in ROM, not a
hardware component .
7. Which memory type is volatile, fast, expensive, and used primarily
for cache?
A) DRAM
B) Flash
C) Magnetic Disk
D) SRAM
Answer: D) SRAM
Rationale: Static RAM (SRAM) uses flip-flops (transistors) to store bits. It
is faster and more expensive than DRAM, does not need refreshing, and
is used for L1, L2, and L3 caches. DRAM is used for main memory .
8. What is a "wafer" in semiconductor manufacturing?
A) The plastic package surrounding the CPU
B) The thin slice of silicon used to fabricate multiple chips
C) The metal heat spreader on top of the CPU
D) The conductive layer connecting transistors
Answer: B) The thin slice of silicon used to fabricate multiple chips
