CXC IT Theory 1999 Attempt ALL questions.
1. A computer computer system system consist consistss of several several hardware hardware devices devices and softwar softwaree components. components. The keyboard, keyboard, mouse and printer printer are all peripheral peripheral devices connected connected to the systems unit. unit. The systems systems unit comprises a Central Processing Unit (CPU) and a component, (A) that holds the data and programs that are currently being used. The CPU in turn, consists of two components. One component (B), (B), directs the internal operations within the CPU; and the other components, (C), is responsible for the manipulation manipulation of the data. In addition, addition, there is another storage storage component, component, (D), which stores stores data and programs that are not currently being used by the CPU. State the components that perform EACH of the functions named A to D and underlined above. (4 marks) Total marks 4
2. Match EACH EACH characte characterist ristic, ic, listed listed A to H below with the the MOST appropriat appropriatee device. Write Write the letter (A,B,etc.) to represent the characteristic and next to EACH letter write the name of the device that matches it.
A. B. C. D. E. F. G. H.
CHARACTERISTIC
DEVICE
Modulates and demodulates signals Accepts voice inputs Allow users to input architectural plans Reads in graphics data Used for printing architectural plans Used for entering text documents Retrieves pricing data from grocery items Used to move the cursor, especially in going
Plotter Keyboard Modem Graphic tablet Microphone Barcode reader Joystick Scanner (8 marks) Total marks 8
3. (a) (b)
State THREE functions functions of an operating operating system. system.
(3 marks)
Identify the types of processing mode that would be suited for the following applications: (1 mark) (i) (i) Mont Monthl hly y payr payrol olll (1 mark) (ii) Transactions at an Automatic Teller Teller Machine (iii) Processing el electricity bi bills (1 mark) Total marks 6
4. (a) (b)
List List THREE THREE ways ways in which which a teache teacherr can use comput computers ers in the classr classroom oom.. (3 marks) Suggest TWO reasons why computers may NOT be used in the classroom. (2 marks) 1
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(c)
5. (a)
State TWO advantages of using computers in the classroom.
(2 marks) Total marks 7
Conver Convertt the decima decimall number number 9010 to a binary number.
(2 marks)
(b)
Convert the binary number 110112 to a decimal number.
(2 marks)
(c)
Add the two binary numbers 11012 and101012, giving your answer as a binary number. (2 marks) (2 marks) Determine the BCD representation of 8710. Total marks 8
(d)
6. (a) (a)
(i) (i)
Ident Identif ify y ONE ONE appl applic icat atio ion n of robo robots ts in indu indust stry ry..
(1 mark)
(ii) (ii)
State State TWO TWO advant advantage agess of using using robo robots ts in in indust industry. ry.
(2 marks)
(iii) (iii)
State State ONE disadv disadvant antage age of usin using g robots robots in in indust industry. ry.
(1 mark)
(b) For EACH of the following following devices, state ONE application application in which the use of the the device is essential: (i)
Scanner
(1 mark)
(ii)
Plotter
(1 mark)
(iii) Modem
(1 mark)
(iv) Magnetic ink-character reader
7. (a)
(1 mark) Total marks 8
In order to secure its data, a company company uses the following following method method for for encrypting encrypting text: A letter is replaced by the letter letter five letters later later in alphabetical order. For example, the letter “A” is replaced by “F”, “B” is replaced by “G”, and so on. Note that the “A” is considered to follow the letter “Z”. (2 marks) (i) What would the word “ESSAY” be stored as? (ii)
What is the meaning of the following text? N LTY NY
(2 marks)
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(iii) (iii)
Within Within many many organi organizat zation ions, s, data data person personnel nel are are stored stored in in a central central loca locatio tion n from whic which h various departments can access relevant information. State THREE problems problems that may arise because of the sharing of this data. (3 marks)
Total marks 9
8.
Progra Programs ms are are writte written n with with the gener general al purpos purposee of solvi solving ng proble problems. ms. However However,, it is unli unlikel kely y that a program will run completely completely error-free on the first first attempt. The process whereby a program is checked to ensure that it does what was designed for is important in the development of the (A) program. There are two main types of errors that can occur: one type of error occurs when the programmer fails to properly think through the solution to the problem, and the other occurs (B) when the programmer does not adequately know the the rules of the programming programming language. It is (C) good practice to perform a manual trace on the program, using appropriately selected input (D) (E) values, which checks each segment of the program. State the proper technical term for EACH of the underlined phrases labeled A to E.
(5 marks)
Total marks 5
9.
(a)
DIFFERENCE = 0 Input A, B If A < = B Then DIFFERENCE = A – B Else DIFFERENCE = B – A Endif Print DIFFERENCE What is printed by the algorithm above if the input values are the following? (1 mark) (i) 20 30 (ii) 100 100 (1 mark) (iii) 50 50 10 (1 mark)
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10.
(i)
(ii) (ii)
Write Write a struct structure ure algori algorithm thm,, which which prompt promptss a user user to enter enter an intege integerr value, value, which which is then, stored in a variable N. The algorithm must then print print each integer from 1 to to N and it corresponding square. Each output line line must show the integer and its its square. You may assume that the user would enter an integer value. (5 marks) Modify Modify the algo algori rithm thm in (i) (i) to to determ determine ine the the sum sum of all the square squares. s. Print Print this this sum if it it is less than or equal to 1000. Otherwise, print the the following message: THE SUM IS GREATER THAN ONE THOUSAND
(5 marks) Total marks 10
