Exams

BUTERE DISTRICT JOINT EVALUATION TEST - 2010
451/1
Computer studies
PAPER 1
MARKING SHEME
1. (a) Purpose of registers in a computer systems. To temporarily hold data that is waiting to be processed or after processing. 1mk

(b) Types of register found in the central processing unit. - Addressing register - Storage register 1mk

2. Comparison between a data matrix and a laser printer. Dot matrix – Low print quality, noisy, Low cost Laser – High print quality, quiet, costly 3mks

3. Convert 3BD16 to Octal 3 – 0111 D – 1101 B – 1011 3BD16 = 01110111101 = 76758 3mks 7 6 7 5

4. (a) Importance of internet to society - Enhances commerce - Improved communication 2mks

(b) Challenges that internet has brought to society - Individual privacy cannot be guaranteed - Moral and cultural issues have been greatly affected - Security as a lot of information can be accessed from the internet. 2mks

5. Difference between (i) Validaty integrity The data entered is valid 1mk (ii) Entity integrity Data is entered in the correct field 1mk (iii) Referential integrity All records entered in the related tables exist in the primary table 1mk

6. Computer crimes taking place in the society - Hacking – Cracking - Eaves dropping - piracy 2mks

7. Three coding systems in computer processing. - ASC11 EBCDIC - BCD BCDIC 3mks

8. (a) Application areas of spreadsheets. - Accounting - Forecasting - Statistical analysis - In mathematical and scientific fields. 2mks

(b) Formulae of the following with reference to cell G20, = F10 + G20 = F10 + &G&20 1mk

9. Modular programming and its advantages. Modular programming is breaking of a program into componets. Advantages -