Computer Science Paper 11
May / June 2016·2210·12 questions
Mock exam: 105 min, official timing
Question paper
Question 1
Question 2
Question 3
Question 4
Question 5
Question 6
Question 7
Question 8
Question 9
Question 10
Question 11
Question 12
Mark scheme
Question 1
1 mark for each correct column Software feature Free Freeware Shareware Software source code can be freely accessed and modified as required → All the features of the full version of the software are not made available;
the full version needs to be purchased first → The original software is subject to all of the copyright laws ✓ ✓ It is possible to distribute modified versions or copies of the software to friends and family → (1 mark) (1 mark) (1 mark) [3]
Question 2
2(a)[1]
media access control [1]
2(b)[3]
Any three from:
– hardware/physical address – unique address/number associated (with network card in) a device/computer – usually 48/64 bits (12/16 hex digits) – first 6/8 digits = manufacturer code/ID of device (NIC) – last 6/8 digits = serial number of device (NIC) [3]
Question 3
3(a)[4]
4/5 matches – 4 marks 3 matches – 3 marks 2 matches – 2 marks 1 match – 1 mark [4]
3(b)[4]
Any four from:
– sensor(s) sends signal/data to microprocessor – signal/data converted to digital (using an ADC) – microprocessor compares signal/data with pre-set/stored value – if sensor(s) signal/data indicates the presence of a person / the door needs to be opened / a match is found / door is closed … – … microprocessor sends a signal to an actuator … – … to operate/drive a motor to open the door [4]
Monitoring the pollution levels in a river Control the switching off and on of street lighting Detection of intruders breaking into a building Monitor the amount of water left in clothes in a drier Monitor acidity levels in the soil in a greenhouse Light sensor Moisture sensor Gas sensor pH sensor Pressure sensor
Question 4
4(a)(i)[1]
serial [1]
4(a)(ii)[3]
Any three from:
– automatically detects the hardware/installs drivers – plug only goes in one way/can’t connect incorrectly – supports different data transmission speeds/a range of data transmission speeds – has become the industry standard/universally used – backwards compatible (with earlier versions of USB ports) [3]
4(a)(iii)[1]
interrupt [1]
4(b)[2]
1 mark each use of printer, max 1 mark per printer. inkjet printer – (small quantities of) documents – photographs 3D printer – (physical) prototype (from CAD) – (physical) model (from a blueprint) [2]
4(c)[3]
1 mark for naming printer + 1 mark for description + 1 mark for application Laser printer – uses toner/powder ink – uses (positive and negative) charged drums // rotating drum – uses static charge – no moving head – faster at printing – high volume output/high speed – producing flyers/leaflets/magazines [3]
This is an example, other types of printers can be credited.
Question 5
5(a)[6]
1 mark for each correct gate, with correct source of input(s) [6]
5(b)[4]
D S T Working Space X 0 0 0 0 0 0 1 0 0 1 0 1 0 1 1 0 1 0 0 1 1 0 1 1 1 1 0 1 1 1 1 0 4 marks for 8 correct X bits 3 marks for 6 correct X bits 2 marks for 4 correct X bits 1 mark for 2 correct X bits [4]
Question 6
6(a)[1]
Any one from:
– protocol ends in “s” – use of https [1]
6(b)[3]
Any three from:
– requests web server to identify itself/view the (SSL) certificate – receives a copy of the (SSL) certificate, sent from the webserver – checks if SSL certificate is authentic/trustworthy – sends signal back to webserver that the certificate is authentic/trustworthy – starts to transmit data once connection is established as secure – if website is not secure browser will display an open padlock/warning message [3]
Question 7
7(a)[2]
1 mark for each correct binary value 0 0 1 1 0 1 0 1 [2]
7(b)[2]
[2] 0 0 0 1 1 0 0 1 0 1 0 0 1 1 1 0 3 5 1 9 4 E 1 mark 1 mark
Question 8
8(a)(i)[2]
Any two from:
– to protect against key logging software/spyware – can stop key presses being recorded – can stop key presses being relayed – drop down boxes cannot be recorded as key presses – drop down boxes can be placed in different location on the screen each time (to overcome screen capture issues) [2]
8(a)(ii)[1]
Any one from:
– hacker never finds all characters on the first hack – makes it more difficult for hackers to find the order of the characters – hacker needs to hack the system several times to gain the whole password – shoulder surfing will not give person full password [1]
8(b)[2]
Any two from:
– fingerprint scanner – face recognition software – retina scanner/iris scanner – voice recognition software [2]
Question 9
9(a)[2]
1 mark for correct check digit and 1 mark for showing the calculation (4 × 1) + (2 × 2) + (4 × 3) + (1 × 4) + (5 × 5) + (0 × 6) + (8 × 7) = 4 + 4 + 12 + 4 + 25 + 0 + 56 = 105 105/11 = 9 remainder 6 check digit is: 6 [2]
9(b)[3]
incorrect check digit [1]
– check digit should be 1 – (3*1) + (2*2) + (4*3) + (0*4) + (0*5) + (4*6) + (5*7) // 3 + 4 + 12 + 0 + 0 + 24 + 35 // Total = 78 – 78/11 gives 7 remainder 1 [2]
1 mark for any correct line of working
Question 10
5/6 matches – 5 marks 4 matches – 4 marks 3 matches – 3 marks 2 matches – 2 marks 1 match – 1 mark [5]
illegal access to a computer system without the owner’s consent or knowledge software that gathers information by monitoring key presses on a user’s keyboard;
the information is relayed back to the originator of the software malicious code installed on the hard drive of a user’s computer or on a web server;
this code will re-direct the user to a fake website without the user’s knowledge creator of code sends out a legitimate- looking email in the hope of gathering personal and financial information from the recipient;
it requires the user to click on the link in the email or attachment a message given to a web browser by a web server;
it is stored in a text file;
the message is then sent back to the server each time the browser requests a page from the server program or code that replicates itself designed to amend, delete or copy data or files on a user’s computer;
often causes the computer to crash or run slowly Pharming Phishing Viruses Hacking Spyware Cookies
Question 11
11(a)[4]
1 mark for each correct row Single track Many concentric tracks Blue laser used to read/ write data Red laser used to read/ write data DVD-RW ✓ ✓ 1 mark DVD-RAM ✓ ✓ 1 mark CD-ROM ✓ ✓ 1 mark Blu-ray disc ✓ ✓ 1 mark [4]
11(b)(i)[3]
Any three from:
– don’t need to “get up to speed” to work properly/no latency – lower/less power consumption/more energy efficient – run cooler – run quieter – data access is faster – occupies less physical space/more compact – lighter, so more suitable for a portable computer/laptop – no moving parts so more reliable/durable in a portable computer/laptop [3]
11(b)(ii)[2]
Any two from:
– HDD is cheaper for larger amounts of storage space – HDD has greater longevity for read/write functions – Expensive to change the technology // HDD are trusted technology – No requirement for the increased speed of SSD [2]
Question 12
12(a)[1]
QR (quick response) Code [1]
12(b)[4]
– A 5 0 (1 mark) 1 0 1 0 0 1 0 1 0 0 0 0 1 mark 1 mark 1 mark [4]
12(c)[3]
Any three from:
- visitor scans the QR code with (the camera on) the mobile device - App is used to read/interpret the QR code - links to a website/opens a document … - … to access local tourist information - can store the QR code to refer to again for the information [3]