AQA Computer science easter revision
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This document provides homework instructions for computer science students over the Easter break. It includes tasks to practice programming in Python using Codecademy, revising data types and network topologies, and completing exercises on binary numbers, flowcharts, databases, and data structures. Students are asked to research advantages and disadvantages of different network topologies. It also provides contact information for teachers if students require assistance.
AQA Computer science easter revision
- 1. Computer Science Easter homework DUE the first lesson back after the break!!!!! Programming practice To become familiar with the programming language Complete the practice python programming tasks on code academy http://www.codecademy.com/learn A great book to learn to program: http://files.swaroopch.com/python/byte_of_python.pdf If you have any difficulties please feel free to contact: p.morris@montomeryschool.co.uk l.harwood@montgomeryschool.co.uk Richard.west@go.edgehill.ac.uk As well as using Montgomery high school on google + or @montyict on twitter Theory Revision
- 2. Data Types Boolean True /false String It is hot outside Integer 457 Floating Point 3.548 What data type is counter? Please define the following Variable Iteration Algorithm Syntax error
- 3. Network Topology Network topology refers to how computers are connected to a network. There are three main types of network topology: bus, ring and star. The bus network In a bus network all the workstations, servers and printers are joined to one cable (the bus). At each end of the cable a terminator is fitted to stop signals reflecting back down the bus. The ring network In a ring network each device (workstation, server, printer) is connected to two other devices, this forms a ring for the signals to travel around. Each packet of data on the network travels in one direction and each device receives each packet in turn until the destination device receives it. The star network In a star network each device on the network has its own cable that connects to a switch or hub. A hub sends every packet of data to every device, whereas a switch only sends a packet of data to the destination device. Pick one of the topologies and research their advantage and disadvantages as well providing a drawing of a typical layout.
- 4. DECIMAL BINARY CORRECT? 0 8 4 2 1 1 8 4 2 1 2 8 4 2 1 3 8 4 2 1 4 8 4 2 1 5 8 4 2 1 0 1 0 1 Example 6 8 4 2 1 7 8 4 2 1 8 8 4 2 1 9 8 4 2 1 10 8 4 2 1 Binary Numbers Binary means two. All numbers in binary are made up of either a 0 or a 1. To work out a decimal number we use a grid like the ones on a left. Decimal number 5 Is there any eights in five? NO! so a zero goes in the eight column. Are there any fours in 5. Yes so we put a 1 in the four column. Leaving one! So we out the one in the 1 column and not the two column Now work out the binary numbers for the other questions.
- 5. Flowchart Create a flowchart which demonstrates the process of ordering a meal at a fast food restaurant.
- 6. Database / SQL Table = Menu Meal-code Name Price Meal-deal 1001 Fish Fingers 1.99 No 1002 Hot Dogs 2.85 No 1003 Turkey Burgers 2.19 No 1004 Jacket Potato 2.50 Yes 1005 Chicken Korma 3.25 No Which of the above would be the primary key? The following SQL statement has been executed to the database table above what would happen? SELECT Name, Price, Meal-deal FROM Menu; Where Meal-code = 1004;
- 7. Data Structures (revision only) The study of data structures is about organising data so that it is suitable for computer processing. Computer hardware looks at storage devices like internal memory and disks as holders of elementary data units (bytes), each accessible through its address (usually an integer). Defining data structures A data structure can be defined as a collection of different data elements, which are stored together in a clear, structured form. In programming, one of the most important design decisions involves choosing which data structure to use. Arrays and linked lists are among the most common data structures and each is applicable in different situations. Data structures: arrays There are situations during the writing of code when programmers need to hold related data as a single item, for example a list of employees’ names or makes of car. One method of doing this would be to assign a variable to each item in the list. One-dimensional arrays A one-dimensional array in Python and PHP is a data structure that allows a list of items to be stored with the capability of accessing each item by pointing to its location within the array. 0 1 2 3 0 A B C D 1 E F G H 2 I J K L 3 M N O P
- 8. The reason why this type of array is referred to as a ‘one-dimensional array’ is that it only uses a single number to point to the position of array elements. Two-dimensional arrays Two-dimensional arrays are a little more complex than the one- dimensional versions, but really they are nothing more than an array of arrays, in other words an array in one row and another in the next row. 4 Q R S T
- 9. Hardware Hardware is a name given to a collection of physical ‘things’ that when put together in a certain way form a ‘system’. Computer hardware: system unit Within a computer system there are basically two types of hardware. The hardware within the system consisting of the CPU (central processing unit), which is situated on a printed circuit board called the motherboard. There is the hard disk drive, the RAM (random access memory), optical drive and other circuit boards such as the graphics and sound cards. These are all regarded as hardware because if you removed the case you could physically touch the devices – although you should not do this unless you know what you are doing. Describe what the purpose of CPU & RAM along with typical specs and costs each. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ __________________________________________________________________