GCSE (9-1) Computer Science - Assessment 1

Hardware, automated systems, programming, binary/denary conversions, ASCII/Unicode, images, sound, and compression methods.

What are input devices?

Devices that allow users to input data into a computer (e.g., keyboard, mouse, scanner).

What are output devices?

Devices that output data from a computer to the user (e.g., monitor, printer, speakers).

What are sensors?

Devices that detect and respond to physical input from the environment (e.g., temperature sensors, motion sensors).

What are robotics?

The branch of technology dealing with the design, construction, operation, and application of robots.

What are automated transport systems?

Systems that use technology to transport goods or people without human intervention (e.g., conveyor belts, automated guided vehicles).

What are data types?

Classifications of data that tell the compiler or interpreter how the programmer intends to use the data (integer, float, string, boolean and list/array).

What is a variable?

A storage location in memory with a name and an associated data type, which can hold different values.

What is selection in programming?

A control structure that allows a program to execute certain sections of code based on conditions (e.g., if statements).

What are loops?

Control structures that repeat a block of code while a specified condition is true (e.g., while loops, for loops).

What is a subroutine?

A set of instructions designed to perform a frequently used operation within a program.

What are parameters?

Variables used in a subroutine that allow you to pass data into it.

What are local and global variables?

Local variables are accessible only within the function they are defined; global variables can be accessed from anywhere in the program.

What is an array?

A collection of elements identified by index or key, allowing for the storage of multiple values in a single variable.

What are 1D and 2D arrays?

1D arrays store a list of values, while 2D arrays store data in a grid format (rows and columns).

How do you convert denary to binary?

Divide the denary number by 2, record the remainder, and repeat with the quotient until it reaches 0. Read the remainders in reverse.

What is the largest number held in x bits?

The largest number is 2^x - 1

What is ASCII?

A character encoding standard that uses 7 or 8 bits to represent characters, allowing for 128 or 256 characters.

What is Unicode?

An encoding standard that allows for the representation of a vast array of characters from different languages and symbols.

What are bitmap images?

Images made up of pixels, where each pixel represents a specific color.

What is pixel resolution?

The number of pixels in an image, usually expressed in width x height (e.g., 1920x1080).

What is color depth?

The number of bits used to represent the color of a single pixel, determining how many colors can be displayed.

What is the process of converting sound to digital data (ADC)?

Analog-to-Digital Conversion (ADC) involves sampling the sound wave at intervals and quantizing the amplitude.

What is the Hertz formula for sound?

Frequency (Hertz) = 1 / Time period (seconds).

How do you calculate file size for sound?

File Size = Duration (seconds) x Sample Rate (samples per second) x Bit Depth (bits per sample).

What is lossy compression?

A compression method that reduces file size by removing some data, potentially affecting quality (e.g., JPEG for images).

What is lossless compression?

A method that reduces file size without losing any data, allowing for the original data to be perfectly reconstructed (e.g., PNG for images).

What is Run Length Encoding (RLE)?

A simple form of compression where sequences of the same data value are stored as a single data value and count.

What is a variable in programming?

A variable is a named storage location in memory that can hold a value which must have a meaningful name.

What are data types in Python?

• Integer: Whole numbers (e.g., 5)

• Float: Decimal numbers (e.g., 5.0)

• String: Text (e.g., "Hello")

• Boolean: True or False values (e.g., True)

What is a list in Python?

fruits = ["apple", "banana", "cherry"]

What are conditional statements?

Conditional statements allow for decision-making in code using if, elif, and else.

if age >= 18:

print("You are an adult.")

else:

print("You are a minor.")

What is a loop in programming?

A loop is used to execute a block of code repeatedly. Common loops include for and while.

for fruit in fruits: print(fruit)

What is an array?

An array is a collection of elements identified by index or key. In Python, lists often serve as arrays.

numbers = [1, 2, 3, 4, 5]

What does a.append(value) do?

Adds value to the end of the list a.

a = [1, 2, 3]

a.append(4)

# a becomes [1, 2, 3, 4]

What does a.remove(value) do?

Removes the first occurrence of value from the list a. If value is not found, it raises a ValueError.

a = [1, 2, 3, 2]

a.remove(2)

# a becomes [1, 3, 2]

What does len(a) do?

Returns the number of elements in the list a.

a = [1, 2, 3]

length = len(a)

# length becomes 3

What does a.index(value) do?

Returns the index of the first occurrence of value in the list a. Raises a ValueError if value is not found.

a = [1, 2, 3]

index = a.index(2)

# index becomes 1

What does a.insert(index, value) do?

Inserts value at the specified index in the list a.

a = [1, 2, 3]

a.insert(1, 5)

# a becomes [1, 5, 2, 3]

What does a.pop() do?

Removes and returns the last item from the list a. If the list is empty, it raises an IndexError.

a = [1, 2, 3]

last_item = a.pop()

# last_item becomes 3, a becomes [1, 2]

What does a.pop(index) do?

Removes and returns the item at the specified index from the list a. Raises an IndexError if the index is out of range.

a = [1, 2, 3]

item = a.pop(1)

# item becomes 2, a becomes [1, 3]