Computing Scholarship 2006/07

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Computing Scholarship 2014
Answer all questions
2 hours
Each section is worth 20%.
Section A - Computer Architecture and Operating Systems
1. List four output devices. [4]
2. Briefly describe two techniques for managing IO in a computer. [4]
3. What is cache memory? [4]
4. In a CPU what is the function of the Control Unit (CU)? [4]
5. What is the function of the kernel of an operating system? [4]
Section B – Files and File Systems
1. What is the difference between lossless and lossy file compression? [4]
2. Briefly describe the disk storage technique known as RAID. [2]
3. What is a file extension? How they are used by an operating system? [2]
4. Explain what is meant by a sequential file, and describe how records are added and how
records are deleted from a sequential file. Why is an indexed sequential file often used in
preference to a standard sequential file? [5]
5. What is the difference between a binary and a text file? [2]
6. Records within a file can be fixed length or variable length. Describe the difference
between fixed and variable length records. Give an advantage and disadvantage of
variable length records. [5]
Section C – The Internet, Networking and Security
1. Briefly explain the meaning of the following terms:
 HTTP
 IP
 HTML
 WWW
In each case your answer should specify what the letters in the term stand for as well as a
brief explanation of the technology being referenced. [8]
2. Routers are used in computer networks. Explain what is meant by the term router and
describe the function of a router in a computer network. [3]
3. What is search engine optimisation? What things can you do to a website in order to
improving the website’s search engine ranking? [3]
4. Explain what is meant by circuit switching and packet switching in a computer network
and give one advantage of packet switching over circuit switching. [3].
5. Describe the TCP/IP layered protocol model. [3]
Section D - Data Representation and Computer Logic
1. Convert the binary number 1001 0111 into decimal. [2]
2. Convert the hexadecimal number ABC into decimal. [2]
3. What are the results of the following bitwise operations on 8-bit variables with no carry:
a. 15 OR 31
b. 15 AND 31
c. NOT 15
d. 255 XOR 16 [8]
4. Why was Unicode invented? [3]
5. Explain how the two’s complement system can be used to represent negative integer
values. Illustrate your answer with an example. [5]
Section E – Programming
1. Procedural programs are constructed using sequencing, iteration and selection. Explain
the meaning of these three terms. [6]
2. Describe two data structures with which you are familiar. [4]
3. Briefly explain the terms below as they are used in object oriented programming:




Encapsulation
Classes
Methods
Inheritance
You may illustrate your answer with examples from any object oriented language with
you are familiar. [4]
4. Write a program in any language with which you are familiar to display the first n
Fibonacci numbers. The value of n should be supplied at run-time by the user.
Output for the program should resemble the following:
Fibonacci Numbers
*****************
How many Fibonacci numbers do you wish to generate? :> 10
The first ten Fibonacci numbers are 1, 1, 2, 3, 5, 8, 13, 21, 34, 55
The rule for generating Fibonacci numbers is simple: the first two numbers in the
Fibonacci sequence are 1 and 1, and then each subsequent number is the sum of the
previous two.
Indicate which programming language you have used. [6]
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