CS 250 Midterm 1 Exam Questions with Correct Answers Latest Update 2025/2026
Electricity always flows in a... - Answers closed circuit
On what part of the clock signal do active low circuits update on? - Answers Falling edge
On what part of the clock signal do active high circuits update on? - Answers Rising edge
Size of a Register - Answers 64 bits (double word)
Computer - Answers A machine that can be programmed to carry out computation
automatically.
Architecture - Answers Conceiving, planning, and designing structures
Computer Architecture - Answers Conceiving, planning, and designing programmable structures
that compute.
Software - Answers A description of a computation expressed in a programming language
including any necessary data and documentation.
How is software written? - Answers In high-level language with specific syntax and semantics.
Purposes of Software - Answers 1. A way to clearly define an algorithm and its data structure(s).
2. Can be executed and understood by both the machine and a human.
What executes software? - Answers An interpreter
Interpreter - Answers A system that directly executes instructions expressed in a programming
language.
How is an interpreter executed? - Answers More interpreters (recursion style) until eventually
the physical machine / circuits are used.
Boolean Operations - Answers not, and, or
How computers make hardware outputs digital... - Answers When a circuits are switching from
on to off (or off to on) and hide the middle voltage from the software. By hiding the transition
from off to on, software sees only boolean (or digital) values.
Mechanical Computers - Answers Computers that use mechanical parts to represent data for
calculations.
Disadvantages of Mechanical Computers - Answers - Parts are not small, so the machine is
large.
- Making parts is expensive.
,- The shape of parts determines the result of computations, so wear and tear can affect the
output.
- Algorithms requiring many steps are slow since there is a max to the speed the parts can
move.
How are computers powered? - Answers By moving electrons.
Electron Properties - Answers - Small mass, can move at near light speed.
- Can control motion with electron field.
- Volume is negligible.
- Electronic computers can be fast, lightweight, and small.
Elements used in Electronic Devices - Answers - elemental silicon (Si) crystals
- Ge and certain alloys - GaAs, SiN
- A two-dimensional, single atomic layer form of carbon (C), called graphene.
- Device cost and performance is affected by choice of elements/alloys.
Capabilities an Interpreter should have... - Answers - Accept input
- Store values (include the memory function)
- Read and write values (and variables)
- Compute (perform functions on values)
- Create output
Memory vs Registers - Answers Memory: 2^62 words (8 bytes, 64 bits), holds massive data
structures which the CPU accessed using load / store instructions.
Registers: 32 of them, holds data for quick access and storage by CPU (for calculations).
What happens when there are more variables than registers? - Answers Less accessed
variables are stored in memory rather than registers.
How do registers and clock signals relate? - Answers With more registers, the clock signal
requires more time to reach each register, so the clock frequency is slower.
Layout of a Computer - Answers - Cores communicate with memory (pass data and
instructions).
- Memory takes in inputs and returns outputs.
, Algebraic Operation - Answers Defined by a table, every input can be mapped to an output.
How are circuits designed? - Answers - Ground and some other voltage.
- Binary circuits (2-system machines)
- Boolean produced. There can be 1 level of energy, or no energy, no in between.
How do electrons move in circuits? - Answers They try to find the way to ground (the end).
Assuming a circuit with 5V input a push button to turn on an LED, what is the output for when
the button is pushed and when it is not pushed? - Answers Not Pushed: Ground
Pushed: 5V
Boolean operations always produce... - Answers A perfect output answer (0 or 1).
Voltage - Answers A measure of energy of electrons at a point in a circuit with respect to
Ground.
How fast can voltage change? - Answers At the speed of light.
Does voltage vary on one wire? - Answers No! Voltage on a wire, including all its branches, is the
same.
Terminal - Answers The end of a wire.
How boolean logic is implemented at a low-level... - Answers Assert if a switch is on or off.
Making truth tables... - Answers Rightmost input column values alternate at 2^0 rate.
The next column to the left alternates at 2^1 rate.
The kth column to the left alternates at 2^k rate.
De Morgan's Law - Answers
PC - Answers Personal Computer - designed to be used at home.
Embedded Computer - Answers A computer inside another device used for running software.
Server - Answers A computer used for running larger programs for multiple users (often
simultaneously), and accessed via a network.
Supercomputer - Answers A class of computers with the highest performance and cost. They
are configured as servers and cost tens to hundreds of millions of dollars.
PMDs - Answers Personal Mobile Devices
Electricity always flows in a... - Answers closed circuit
On what part of the clock signal do active low circuits update on? - Answers Falling edge
On what part of the clock signal do active high circuits update on? - Answers Rising edge
Size of a Register - Answers 64 bits (double word)
Computer - Answers A machine that can be programmed to carry out computation
automatically.
Architecture - Answers Conceiving, planning, and designing structures
Computer Architecture - Answers Conceiving, planning, and designing programmable structures
that compute.
Software - Answers A description of a computation expressed in a programming language
including any necessary data and documentation.
How is software written? - Answers In high-level language with specific syntax and semantics.
Purposes of Software - Answers 1. A way to clearly define an algorithm and its data structure(s).
2. Can be executed and understood by both the machine and a human.
What executes software? - Answers An interpreter
Interpreter - Answers A system that directly executes instructions expressed in a programming
language.
How is an interpreter executed? - Answers More interpreters (recursion style) until eventually
the physical machine / circuits are used.
Boolean Operations - Answers not, and, or
How computers make hardware outputs digital... - Answers When a circuits are switching from
on to off (or off to on) and hide the middle voltage from the software. By hiding the transition
from off to on, software sees only boolean (or digital) values.
Mechanical Computers - Answers Computers that use mechanical parts to represent data for
calculations.
Disadvantages of Mechanical Computers - Answers - Parts are not small, so the machine is
large.
- Making parts is expensive.
,- The shape of parts determines the result of computations, so wear and tear can affect the
output.
- Algorithms requiring many steps are slow since there is a max to the speed the parts can
move.
How are computers powered? - Answers By moving electrons.
Electron Properties - Answers - Small mass, can move at near light speed.
- Can control motion with electron field.
- Volume is negligible.
- Electronic computers can be fast, lightweight, and small.
Elements used in Electronic Devices - Answers - elemental silicon (Si) crystals
- Ge and certain alloys - GaAs, SiN
- A two-dimensional, single atomic layer form of carbon (C), called graphene.
- Device cost and performance is affected by choice of elements/alloys.
Capabilities an Interpreter should have... - Answers - Accept input
- Store values (include the memory function)
- Read and write values (and variables)
- Compute (perform functions on values)
- Create output
Memory vs Registers - Answers Memory: 2^62 words (8 bytes, 64 bits), holds massive data
structures which the CPU accessed using load / store instructions.
Registers: 32 of them, holds data for quick access and storage by CPU (for calculations).
What happens when there are more variables than registers? - Answers Less accessed
variables are stored in memory rather than registers.
How do registers and clock signals relate? - Answers With more registers, the clock signal
requires more time to reach each register, so the clock frequency is slower.
Layout of a Computer - Answers - Cores communicate with memory (pass data and
instructions).
- Memory takes in inputs and returns outputs.
, Algebraic Operation - Answers Defined by a table, every input can be mapped to an output.
How are circuits designed? - Answers - Ground and some other voltage.
- Binary circuits (2-system machines)
- Boolean produced. There can be 1 level of energy, or no energy, no in between.
How do electrons move in circuits? - Answers They try to find the way to ground (the end).
Assuming a circuit with 5V input a push button to turn on an LED, what is the output for when
the button is pushed and when it is not pushed? - Answers Not Pushed: Ground
Pushed: 5V
Boolean operations always produce... - Answers A perfect output answer (0 or 1).
Voltage - Answers A measure of energy of electrons at a point in a circuit with respect to
Ground.
How fast can voltage change? - Answers At the speed of light.
Does voltage vary on one wire? - Answers No! Voltage on a wire, including all its branches, is the
same.
Terminal - Answers The end of a wire.
How boolean logic is implemented at a low-level... - Answers Assert if a switch is on or off.
Making truth tables... - Answers Rightmost input column values alternate at 2^0 rate.
The next column to the left alternates at 2^1 rate.
The kth column to the left alternates at 2^k rate.
De Morgan's Law - Answers
PC - Answers Personal Computer - designed to be used at home.
Embedded Computer - Answers A computer inside another device used for running software.
Server - Answers A computer used for running larger programs for multiple users (often
simultaneously), and accessed via a network.
Supercomputer - Answers A class of computers with the highest performance and cost. They
are configured as servers and cost tens to hundreds of millions of dollars.
PMDs - Answers Personal Mobile Devices
