9608_s20_qp_11
A paper of Computer Science, 9608
Questions:
9
Year:
2020
Paper:
1
Variant:
1
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1
A computer program makes use of data validation routines and verification of data input. Complete these two sentences about data validation and verification. 1. checks that the data entered is reasonable. One example is . 2. checks that the data entered is the same as the original. One example is . The program is installed on a computer system that has security measures in place to protect its data. Complete the following table. Security measure Description Data are written on two or more disks simultaneously. Encryption A copy of the data is taken and stored in another location.
1. Theory Fundamentals  →  1.6. Security, privacy and data integrity
Open
2
Kal teaches Computer Science and uses different devices when teaching his students. Tick (✓) one or more boxes on each row to indicate whether each device is an input device, an output device, or both. Device Input Output LCD monitor Microphone Keyboard Touchscreen Kal has built a 3D printer to show students how it works. The steps 1 to 9 describe the basic internal operation of a 3D printer. The following five statements are used to complete the sequence of steps. A A stepper motor moves the nozzle into position B A fan cools the layer C The software splits the object into slices D The nozzle extrudes the molten plastic E The data about the slices is sent to the printer Write one of the letters A, B, C, D or E in the appropriate step to complete the sequence. 1. The object is designed using Computer Aided Design (CAD) software 2. 3. 4. The solid plastic is melted and transferred to the nozzle 5. 6. 7. The steps 5 to 6 are repeated until the layer is complete 8. 9. The steps 4 to 8 are repeated for each subsequent layer The 3D printer has both RAM and ROM. Describe the purpose of RAM and ROM in a 3D printer. RAM ROM
1. Theory Fundamentals  →  1.3. Hardware
1. Theory Fundamentals  →  1.4. Processor fundamentals
Open
4
A digital camera takes a bitmap image. The image is 2000 pixels wide by 1000 pixels high with a colour depth of 24-bits. Calculate an estimate of the file size for the image. Give your answer in megabytes. Show your working. Working Answer MB A second image is taken, this time in black and white. It has the same number of pixels, but the file size is smaller. Explain why the file size is smaller. The digital camera allows a user to add text to an image. The text is encoded as ASCII values. The table shows the ASCII denary values for five characters. Character ASCII denary value a b c d e Give the 8-bit binary value for the ASCII character ‘b’. Complete the table by writing the ASCII denary value for the character ‘t’ and its hexadecimal equivalent. Character t ASCII denary value Hexadecimal value
1. Theory Fundamentals  →  1.1. Information representation
Open
6
A processor has one general purpose register, the Accumulator (ACC), and an Index Register (. The table gives three assembly language instructions for loading data into the ACC. It also identifies the addressing mode used for each instruction. Instruction Addressing mode A LDM #193 Immediate B LDD 193 Direct C LDX 193 Indexed State the contents of the Accumulator after each of the instructions A, B and C are run. A B C Name two other addressing modes. The ACC is a general purpose register. The IX is a special purpose register. Identify two other special purpose registers used in the fetch-execute cycle and describe their role in the cycle. Register 1 Role Register 2 Role
1. Theory Fundamentals  →  1.4. Processor fundamentals
Open
7
A driving school teaches people how to drive cars. The school has a relational database, DRIVING_SCHOOL, to store information about instructors, students, lessons and the cars used by instructors. INSTRUCTOR(InstructorID, FirstName, LastName, DateOfBirth, Level) CAR(Registration, Make, Model, EngineSize) INSTRUCTOR_CAR(InstructorID, Registration) STUDENT(StudentID, FirstName, LastName, DateOfBirth, Address1) LESSON(LessonID, StudentID, InstructorID, LessonDate, LessonTime) Give two benefits to the driving school of using a relational database instead of a flat file. Complete the entity-relationship diagram for the database DRIVING_SCHOOL. INSTRUCTOR INSTRUCTOR_CAR LESSON CAR STUDENT The table shows some sample data for the table INSTRUCTOR. InstructorID FirstName LastName DateOfBirth Level Ins01 Jayden Han 05/06/1974 Ins02 Freda Choi 06/02/1978 Ins03 Kelly Kim 01/12/1966 Ins04 Santana Thompson 09/09/1985 Complete the Data Definition Language (DDL) statement to create the table INSTRUCTOR. ………………………………………………………………………… TABLE INSTRUCTOR( InstructorID VARCHAR(5), FirstName VARCHAR(15), LastName VARCHAR(15), DateOfBirth DATE, Level ………………………………………………………………………… , ………………………………………………………………………… (InstructorID) ); The table STUDENT needs an additional field to store the student’s telephone number, for example 012-3456. Write a Data Definition Language (DDL) statement to add the new field to the table STUDENT. Write a Data Manipulation Language (DML) statement to return the date and time of all future lessons booked with the instructor whose InstructorID is Ins01.
1. Theory Fundamentals  →  1.8. Database and data modelling
Open
8
Bart plays computer games on his stand-alone games console. The games console has an operating system. Describe the tasks performed by the operating system to manage the main memory in the games console. The computer games are written in a high-level language. Bart does not need a compiler or an interpreter to run the games he buys for his console. Explain why the games run without the need for a compiler or an interpreter. When Bart is at work, he connects his work laptop to his employer’s Local Area Network (LAN). The LAN has both a router and a gateway. Give two similarities and one difference between a router and a gateway. Similarity 1 Similarity 2 Difference
3. Advanced Theory  →  3.2. Communication and Internet technologies
1. Theory Fundamentals  →  1.5. System software
Open
9
Utility programs are examples of system software. Complete the table by writing the name of the utility program for each description. Description Utility program Reorganises files on a disk to improve efficiency Scans a hard disk to identify bad sectors Prepares a hard disk for first use File compression is one example of a utility program. Tick (✓) one box on each row to indicate whether the action is an example of lossy compression or lossless compression. Action Lossy Lossless Reducing the resolution of an image Using run-length encoding on a text file Reducing the sampling rate of a sound file
1. Theory Fundamentals  →  1.5. System software
Open