Describe the octal number system.
(a) Describe the octal number system.
(b) Convert each of the following to the number system indicated:
(i) 111.1012 to decimal;
(ii) 14.687510 to binary.
(c) Convert the number -17 10 into 8-bit:
(i) signed magnitude representation;
(ii) two’s complement.
(d) Perform the arithmetic operation
110.112 + 11.0112
(a) Characteristics of octal number system.
The following is an extract from a document created using a wordprocessor.
Identify six formats that have been applied on the extract.
(b) State three tools in a wordprocessor that would help a user to minimize spelling mistakes when creating a document.
(c) The following is an extract of a spreadsheet created to manage sales. Use it to answer the questions that follow.
(i)Write a formula that will compute the number of items whose unit price is more than 10,000.
(ii) If the formula = $R2 * C$2 was placed in cell D2, state the output if it was copied to D3.
(d) A school administers examinations to all students in sciences, humanities and languages. Use the entities; EXAMINATIONS, STUDENTS, SCIENCES,HUMANITIES and LANGUAGES to illustrate a network database model.
(a) Formats applied
State the role of each of the following data communication devices:repeater and router
(b) Figure 3 shows a network based on the bus topology.
(i) Identify the component labelled P.
(ii) State the function of the component labelled P.
(c) Students of Neema Secondary School formed an environmental club with a goal of taking part in environmental conservation activities. Outline three ways in which they can use the internet to achieve this goal.
(d) (i) A company has three branches A, B and C where A is the headquarter. The local area network (LAN) at A is directly connected to the LAN at B and directly to the LAN at C. Explain two benefits of having the LAN at B also directly connected to the LAN at C. (4 marks)
(ii) State three ways in which a company can protect its computer network from hackers.
(a) (i) Repeater
(ii) Terminator in a backbone is used to prevent data signal from bouncing back/absorb signals.
(c) Use of internet in environmental conservation club
With the aid of a diagram. describe time sharing mode as used in computer data processing.
(b) A company’s management has opted to use computers to process data. State four factors that the management needs to consider when selecting the company data processing mode.
(c) Explain the purpose of each of the following in system documentation:
(î) user manual;
(ii) sample data:
(iii) table descriptions.
(a) Time-sharing mode
This is a processing mode in which a central processor serves two or more users with different requirements. The processor time is divided equally
among the tasks in the queue. A user whose task requirements are more than is apportioned is send back to the queue. For example, four jobs requiring times t1, t2, t3 and t4 to complete is apportioned equal time in each round until when they are done.
(b) Factors to consider when selecting data processing mode
State two advantages of using low level programming languages.
(b) Other than flowcharts, state three tools that can be used to present an algorithm.