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WorksheetsEdexcel GCSE Computer Science
Total questions: 33
Worksheet time: 18mins
Name
Class
Date
1.
An algorithm is
a)
sequence of steps to complete a task
b)
instructions for a computer to follow
c)
breaking a problem down into chunks
d)
a flowchart
2.
The following lists represent 3 passes of a sorting algorithm. Which algorithm is being used to sort the list?
4 5 9 6 2 7
4 5 6 2 7 9
4 5 2 6 7 9
4 5 9 6 2 7
4 5 6 2 7 9
4 5 2 6 7 9
a)
Bubble Sort
b)
Selection Sort
c)
Insertion Sort
3.
What is pseudocode?
a)
Simplified programming language, that is not a specific language
b)
Complicated programming language
c)
Simple programming language, which is linked to a specific language
d)
A type of cheese
4.
How many megabytes are in 1 gigabyte?
a)
1024
b)
1
c)
1024 x 10 = 10240
5.
What is the process called for converting analogue sound into binary (digital format)?
a)
Conversions
b)
Sampling
c)
Bit Rate
d)
Converting
6.
What is sound measured in?
a)
Gigabytes
b)
bits
c)
Hertz
d)
Bytes
7.
What is the usual sample rate?
a)
20,000Hz
b)
48,000Hz
c)
3,000Hz
d)
50,000Hz
8.
What is bit depth?
a)
Number of bits assigned to each sample
b)
Rate at which the binary is calculated
c)
How deep the sound can go
d)
The speed of the sound wave
9.
What is a factor that effects the samples taken per second from an analogue sound wave?
a)
File Size
b)
Amplitude
c)
Tone
d)
Resolution
10.
Colour depth refers to:
a)
How many bits are used in a file to store colour information in every pixel
b)
Resolution divided by the number of colours in an image.
c)
Degree of file compression applied to an image file.
d)
Repeated resampling of an image.
11.
How many colours do we get from 3 bits?
a)
2 colours
b)
4 colours
c)
8 colours
d)
24 colours
12.
The higher the colour depth, the _________the image file size.
a)
Smaller
b)
Larger
13.
What is the calculation to work out how many bits a bitmap is?
a)
height * width * colour depth
b)
height / width * colour depth
c)
height - width + colour depth
d)
height * width / colour depth
14.
What is the calculation to work out how many bytes a bitmap is?
a)
height * width * colour depth / 8
b)
height / width * colour depth / 8
c)
height - width + colour depth / 8
d)
height * width / colour depth / 8
15.
A bitmap image is 20 pixels high and 5 pixels wide, with a colour depth of 2 bits. How many bits is this image?
a)
200 bits
b)
100 bits
c)
500 bits
d)
150 bits
16.
Decomposition
a)
Precise, English-like description of an algorithm. It has no specific syntax, so input name and if name is bob are valid instructions.
b)
Boolean operator that returns a true value only if both operands are true
c)
Breaking a problem into a number of sub-problems, so that each sub- problem accomplishes an identifiable task, which might itself be further subdivided.
d)
This translator converts a high-level language into machine code one line at a time and then executes it, it's slower but interpreted code is quicker to write and easier to update
17.
Abstraction
a)
Programing languages designed to make it easier for humans to understand and write computer programs, than using low-level languages. Examples include Python and C#.
b)
Coding a second programming construct inside the first. You can do this with selection and iteration
c)
A collection of related data items called fields, often stored as a row in a database, it represents something in the real world like a person or product
d)
The process of removing unnecessary detail from a problem.
18.
Real
a)
A function that returns the numeric location of a character within a larger string (counting from 0)
b)
A data type also called floating point numbers, they have a decimal part, for example 1.5, 0.935 or the value of Pi
c)
The name we give to variables, constants and subroutines, it should be meaningful
d)
A sorting algorithm that passes over the list many times, swapping adjacent items if they are in the wrong order. Not very efficient.
19.
Integer
a)
A statement that starts a condition-controlled loop with the condition at the end in an UNTIL statement, it will run once even if the condition is false
b)
A type of translator which converts a high-level language in to machine code all at once
c)
The data type of a whole number e.g. 5, 999 or -4
d)
Repeats instructions a until a condition is met, also called "condition-controlled". Uses WHILE or REPEAT... UNTIL in high-level languages
20.
Boolean
a)
This data type has only two values, TRUE and FALSE
b)
A programming construct where instructions follow, one after the other
c)
An error that occurs when the code runs but fails during the operation. Usually caused by file handling problems or data types being incorrect.
d)
A subroutine which does not return a value. For example it might redraw the screen or write a record to a file
21.
String
a)
This statement starts a definite iteration with the amount of iterations at the start, it will run a set number of times.
b)
An error because the rules of the language have been broken, such as forgetting a bracket or mis-spelling a keyword
c)
This data type stores a series of characters, e.g. "Zak", "MK44 5AB" or "123456789"
d)
The arithmetic operator that divides one operand by another e.g. total / 7
22.
Sequence
a)
A data type also called floating point numbers, they have a decimal part, for example 1.5, 0.935 or the value of Pi
b)
A programming construct where instructions follow, one after the other
c)
A visual representation of an algorithm using specific shapes including rectangle, diamond and parallelogram.
d)
A low-level language which uses mnemonics such as LDA, ADD to represent machine code instructions
23.
Selection
a)
Programing languages designed to make it easier for humans to understand and write computer programs, than using low-level languages. Examples include Python and C#.
b)
A searching algorithm that divides the search space in half each time until it finds the target, faster than linear but requires the array to be sorted
c)
A program which converts source code into code which the processor can execute, this can be a compiler, interpreter or assembler
d)
A programming construct where the code makes a decision, and takes one of several branches, usually coded with IF-THEN-ELSE
24.
Logic error
a)
This statement starts a condition-controlled loop with the condition at the start, so the loop will only begin if the condition is true
b)
Precise, English-like description of an algorithm. It has no specific syntax, so input name and if name is bob are valid instructions.
c)
A low-level language which the CPU can process directly, and consists of only binary codes which are very hard to write directly, to change and to debug
d)
An error that occurs when code runs but produces unexpected results. E.g. adding instead of subtracting or stopping a loop too soon. It is detected by systematic testing with a trace table
25.
Run-time error
a)
An error that occurs when the code runs but fails during the operation. Usually caused by file handling problems or data types being incorrect.
b)
This data type has only two values, TRUE and FALSE
c)
A function that returns the numeric location of a character within a larger string (counting from 0)
d)
Extreme test data at the edges of the valid range. Phone battery percentage must be between 0 and 100, so these test data values would be -1, 0, 100 and 101
26.
Testing
a)
The systematic process of running a program repeatedly with different input data and checking the output is as expected, revealing errors
b)
A subroutine which returns a value. It might return a random dice roll, calculate a ticket price or determine your exam grade
c)
This statement starts a condition-controlled loop with the condition at the start, so the loop will only begin if the condition is true
d)
A variable declared in a subroutine definition, a and b are parameters in this code: SUBROUTINE add(a, b) result ← a + b RETURN result ENDSUBROUTINE
27.
Low-level language
a)
A type of translator which converts a high-level language in to machine code all at once
b)
Programing languages designed to make it easier for humans to understand and write computer programs, than using low-level languages. Examples include Python and C#.
c)
A searching algorithm which looks at every element in turn until it finds the target, it is slow but works even on unsorted data
d)
Programming languages which are a much closer representation to the instruction set of the processor. These include assembly language and machine code.
28.
High-level language
a)
An error that occurs when the code runs but fails during the operation. Usually caused by file handling problems or data types being incorrect.
b)
This data type has only two values, TRUE and FALSE
c)
A subroutine which does not return a value. For example it might redraw the screen or write a record to a file
d)
Programing languages designed to make it easier for humans to understand and write computer programs, than using low-level languages. Examples include Python and C#.
29.
Translator
a)
Joining two strings together, usually uses the + operator, for example fullname = firstname + lastname
b)
A program which converts source code into code which the processor can execute, this can be a compiler, interpreter or assembler
c)
Precise, English-like description of an algorithm. It has no specific syntax, so input name and if name is bob are valid instructions.
d)
A sorting algorithm that passes over the list many times, swapping adjacent items if they are in the wrong order. Not very efficient.
30.
Interpreter
a)
A visual representation of an algorithm using specific shapes including rectangle, diamond and parallelogram.
b)
A type of translator which translates assembly language in to machine code
c)
A program which converts source code into code which the processor can execute, this can be a compiler, interpreter or assembler
d)
This translator converts a high-level language into machine code one line at a time and then executes it, it's slower but interpreted code is quicker to write and easier to update
31.
Compiler
a)
Where inputs, processing and outputs are taking place within an algorithm.
b)
The name we give to variables, constants and subroutines, it should be meaningful
c)
The numeric value of a character in a the character set. In ASCII, "A" is 65
d)
A type of translator which converts a high-level language in to machine code all at once
32.
Bubble Sort
a)
Subroutines can be developed in isolation, independently or separately; Easier to discover errors/testing is more effective (than without a structure); Subroutines can be updated without affecting the overall program.
b)
Techniques for developing programs:.Writing re-useable functions. Giving functions / variables meaningful names. Passing parameters (values) to the function. Functions return values.
c)
A sorting algorithm: 1) Each item in a list is compared to the one next to it. 2) If first item is greater - swap places. 3) Compare next items - until end of list is reached. 4) Repeat the process until the array is sorted.
d)
AND, OR, NOT
33.
Merge Sort
a)
A sorting algorithm - example of a divide-and-conquer algorithm: 1) splits list in half (2nd sub-list should start at middle item). 2) keeps repeating step one on each sub-list until all the lists only contain one item. 3) merge pairs of sub-lists and sort the items into the right order. 4) repeat step 3 until you have merged all the sub-lists together.
b)
File size = colour depth x number of pixels
c)
erroneous, boundary, normal
d)
Subroutines can be developed in isolation, independently or separately; Easier to discover errors/testing is more effective (than without a structure); Subroutines can be updated without affecting the overall program.
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