CWSS 2020 Computing P1 Solution

COMMONWEALTH SECONDARY SCHOOL PRELIMINARY EXAMINATION 2020 COMPUTING Paper 1 (Theory) Sec 4 E/4NA Mark Scheme Qn Answer Marks 1 Statement Register Main Memory Secondary Storage Data is lost during power interruption ✔ ✔ Non-volatile memory ✔ Slowest accessing speed ✔ Storage space directly used by the arithmetic logic unit and the control unit ✔ Used to transfer large amounts of data from one device to another ✔ 2 Licence Description Free and Open Source • • Software that is free for use for a period after which users will need to pay a fee to continue to use it. Public Domain • • Software where unauthorised copying of it is prohibited and its source code is kept secret. Freeware • • Software that is available as “lite” version where users may use at no cost. Shareware • • Software that is available for users to use, copy, study and modify. Proprietary • • For intellectual property that have expired or simply surrendered. 3 (a) (i) 8910 = 6410 + 1610 + 810 + 110 = 26 + 24 + 23 + 20 = 010110012 3 (a) (ii) 910 = 10012 and B16= 10112 Thus, 9B16 = 1001 10112 = 12810 + 1610 + 810 + 210 + 110 = 15510 9B16 = 16 x 9 + 11 = 15510 1

Qn Answer Marks 3 (a) (iii) 11102 = 8 + 4 + 2 and 01012 = 4 + 1 = 1410 = 510 = E16 = 516 Thus, 111001012 = E516 3 (b) (i) Unicode can encode more characters of different languages than ASCII. 3 (b) (ii) RGB colour codes, memory dumps, network address, ASCII and Unicode, URL Encoding (Any TWO) 4 Wired: Network devices are connected by a physical medium such as cables. Wireless: Signals are transmitted in the form of electromagnetic waves such as radio waves and microwaves. Wired: Less convenient when expansion required as additional wiring will be needed. Wireless: Network can be expanded easily with existing equipment. Wired: Less convenient to use as equipment needs to be connected by cables at all time. Wireless: More convenient as one can work from any location within the wireless network’s coverage area. (Any TWO) 5 (a) (i) 1. Technology and software have been able to reduce the time, cost and effort needed for payments, investments, fundraising, trading and/or data analytics for both business and individuals. 2. Algorithmic trading which is the study and refinement of algorithms to make trading decisions at speed not possible by human being can generate profits at a speed and frequency that is impossible for a human trader. 3. Artificial intelligence can be used to calculate interest rates and home values by using historical pricing charts to develop a model that more accurately predicts the financial future by taking numerous factors into account. 4. As computers can handle large volumes of information, they can take over the manual work of analyzing data and creating meaningful reports and so will be more efficient in tasks such as detecting and preventing fraud.

Qn Answer Marks 5. The use of softw