Deconstructing Exam Questions

LAZSTA2010

Greg PittDeconstructing Exam Questions

Changes to the HSC beginning in 2010Section I

Part A20 marks 20 multiple choice (Note this change)Part B55 marks Written response (Extended answer)

Section II25 marks Option (one from the following)- Polymers- Preservatives and Additives- Pharmaceuticals - Disasters - Space ScienceHSC Timetable 2010Download from http://www.boardofstudies.nsw.edu.au/events/

BOS Important notice

Question 19 (2009 HSC)

HSC Outcomes A student

Outcomes-related questions [Outcome H2]Explain the effect of pulling down on the rubber sheet. (2M)Outline why models, such as the one shown, are used in science. (2M)

Outcomes-related questions [Outcome H2]Explain the effect of pulling down on the rubber sheet. (2M)Outline why models, such as the one shown, are used in science. (2M)

HSC 2009Question 20 (6 marks)Describe the beneficial and detrimental effects of soaps and soapless detergents on the environment. (6M)

HSC 2009Question 20 (6 marks)Describe the beneficial and detrimental effects of soaps and soapless detergents on the environment. (6M)

HSC 2009Question 27 (6 marks)A fax machine firstly converts an image into information. The information is transmitted through a copper wire and then transmitted using an optical fibre.Describe the processes that take place at each of these three steps.

HSC 2009Question 27 (6 marks)A fax machine firstly converts an image into information. The information is transmitted through a copper wire and then transmitted using an optical fibre.Describe the processes that take place at each of these three steps.

Sample answer: The document is scanned by a beam of light along very thin lines. The light reflects differently from different marks on the page. The reflected light is detected by a photocell. The photocell converts the incident light into electrical voltages. This signal carriers information along a copper wire. For optical fibre, the electrical energy is converted to light for transmission, and the signal is digitally encoded.

HSC 2008 Question 23Discuss the use of visible light in communication systems. (6M)

HSC 2008 Question 23Discuss the use of visible light in communication systems. (6M)

Visible light can be used in simple communication systems such as traffic lights and lighthouses. The advantages of using light in such communication systems are that light travels at very high speeds and the information is sent virtually instantaneously. The ability of light to be reflected allows the information to be sent through underground cables between the source and destination. One disadvantage of light is that it cannot always be used to transmit information through the atmosphere during the day due to interference with natural light. This is why lighthouses only operate at night-time.HSC 2007 Question 19Question 19 (5 marks)Relate the properties of pesticides and body hygiene products to the precautions needed when using and handling each type of chemical.

Notes from the markers: Better responses identified precautions to follow when using both these types of chemicals and then related them to specific properties of pesticides and of body hygiene products.The weakest responses only included precautions with little or no mention of properties of either type of chemical.HSC 2007 Question 24 (b)Explain reasons for the increased use of fibre optics in communication. (4 marks)Reasons two examplesGreater data carrying capacityReduced cost (per megabyte of data)ExplanationGreater data carrying capacity is possible because using light (IR), it is possible to switch the light on and off (hence binary code) at extremely high frequencies and hence more data bits per second.Reduced cost (per megabyte of data) has happened because each fibre can carry more data per second and many fibres can be laid simultaneously at little extra cost (redundancy for future).HSC 2007 Question 25Relate TWO properties of microwaves to their use in communication through air and space. (4 marks)Two properties of microwavesTravel very fast at the speed of lightTravel through a vacuum as well as the airRelationship between property and useTravel very fast this makes almost instantaneous communication possible between points on Earth and to/from satellites in orbit around the Earth.Travel through a vacuum as well as air this makes it possible to communicate using satellites as well as through the air making mobile phone communication possible.HSC 2007 Question 27Assess the impacts that changes in communication systems have had on society. (6 marks)HSC 2006 Question 18 (b)Explain why knowledge of the solubility of materials is important to the way medications are administered. (4 marks)HSC 2006 Question 26Technological advances have enabled human communication to change from methods that were mainly used over short distances, to a range of systems that allows worldwide communication to occur.Analyse the relationship between the development of worldwide communication systems and the changes that these systems have produced in society. (7 marks)

Mandatory First-hand Investigationsperform a first-hand investigation to observe ways in which waves can be modulated to carry different types of information(Syllabus dot point)

Q27 2002 HSCMandatory Investigationsperform a first-hand investigation to observe ways in which waves can be modulated to carry different types of information (Syllabus dot point)

Deconstructing a QuestionExplain why a communications satellite must be at a height at which its revolution period is the same as that of the Earths period of rotationRelate cause and effect; make the relationships between things evident; provide why and/or howSatellite dedicated to sending of information between two points on the EarthAltitude, distance above the Earths surfaceTime taken to travel once around the Earth, also called the orbital periodequalTime taken for the Earth to rotate once on its axis, axial rotational period, 24 hOther Useful Resources (for Biology teachers)Casseopiea Evolution http://www.cassiopeiaproject.com/videos2.php (Download from iTunes)(Or from YouTube) http://www.youtube.com/watch?v=Hzx2F8fqyEAThis is an excellent series of 6 programs about evolution and other topic areas are available.