Define the term screen resolution.

Describe two issues resulting from the website being viewed on various devices, such as desktops and smartphones.

Explain the role of the operating system (OS) in terms of managing the hardware resources.

A washing machine uses a control system.

The microprocessor controls the washing machine and its actions. To complete the wash and rinse process the user selects the program, loads the washing machine and pushes the start button.

Describe the interaction between the sensors, microprocessors and output transducers in this situation.

Award [1 max]
Screen resolution is the number of pixels a screen can display (horizontally and vertically). (For example, the screen can show 1024 pixels horizontally and 768 vertically);

Award [4 max]
Screens that are different sizes (for example, 3–6 diagonal inches for a phone, and 9–12 diagonal inches for a tablet, size of 13–17 inches for a notebook screen, and a desktop screen size of 20–30 inches);
can still have the same screen resolution (for example, a laptop could have a 13-inch screen with a resolution of 1280 x 800 and a desktop computer could have a 17 inch monitor with the same 1280 x 800 resolution);
but physically smaller screen will not show less of the website;
the screen with the higher resolution will be able to show you more of the website because that screen has more pixels and the image will be sharper;
but elements on the screen (icons and text) will look smaller;

Most mobile displays currently have screens with fewer pixels than desktop displays and are physically smaller;
typing on small on-screen keyboards is difficult;
less precision (clicking a 12-pixel-high text link with a mouse is no problem but tapping the same link with fingers could be difficult);
there is no mouse pointer so there is no concept of "hovering" over a page element/ remaining in an uncertain state;
most modern touch screens allow zooming;
allow the user to perform gestures using one or more fingers, such as swiping/pinching;

Note: Award marks not only for issues for a viewer but also for issues for a creator of the interface.

Award [4 max]
OS controls all the activities of computer system and acts as an interface between user and hardware;

Thus the role of OS is
to keep track of who is using which resource;
to grant resource requests;
to mediate conflicting requests from different users/programs;
to allocate time to different programs or different users/ each one gets their turn to use that resource (for example printer);
to allocate space for different users, each one gets a part of the resource (for example sharing main memory/ hard disk);

Award [6 max]
Award [2 max] for evidence that:
Sensors (input devices) detect/measure the water level;
sensors detect/measure the temperature (of the water);
sensors detect/measure the dampness/moisture level of the clothes;
sensors also detect movement of the machine's drum and other associated actions;

Sensors continuously take readings/measurements (in the context of above) and send these readings to the processor;

Award [2 max] for evidence that:
processor controls sensors, valves and actuators responsible for controlling the parts that clean clothes;
processor determines what actions the machine should take next;
the washing machine has been programmed/ it goes through a process of running its internal programs;

processor compares readings with pre-set values (in the context of the various sensors);
if the readings fall outside of the specified range, the processor sends a message to the output transducer to switch on/off ... (in the context of part of the washing machine);

Award [2 max] for evidence that:
output transducers are used for turning on and off devices that control the rest of the machine;
such as the motors that spin the tub;
or the water pump;

Example:
once the start button is pushed the washing machine begins to dump water into the drum, a sensor will detect that the water level has been reached;
based on the setting, the processor will allow the water to flow only to a predetermined level;
it will send the signal to output transducers to shut off the water;
and begin the agitation process;
once the timer tells that it is time, processor sends signal to output transducer to stop agitating;
it then begins the spin process/ removing the dirty water from the machine at the end of the spin cycle, the washing machine's processor sends signal to turn on the water pump and sucking it out of the machine;

Mostly a well answered question.

Mostly a well answered question.

Candidates mostly gave good responses for this question.

A wide variety of answers and quality of answers was seen for this question covering the full mark range. Candidates who were able to fully describe the interaction between the sensors, microprocessors and output transducers and the steps involved generally scored quite highly.