IGCSE COMPUTER SCIENCE - INPUT &
OUTPUT DEVICES EXAM QUESTIONS
AND ANSWERS
Camera - Answer-Light passes through the lens onto a light-sensitive cell. The light
sensitive cell is composed of pixels forming an image
Resistive Touchscreen - Answer-The touchscreen is made out of multiple layers and
once it is pressed, the circuit is completed and the coordinates of where the circuit has
been complete is recorded.
Capacitive Touchscreen - Answer-When the top layer of glass is touched, the electric
current chances and the coordinates where the screen was touched is determined by
the microprocessor.
Infra-red touch screen - Answer-Has a grid of lasers and when it is interrupted it outputs
a x,y coordinate
- can do multi touch
- is expensive
Laser Printer - Answer-Drum is positively charged, a laser then makes some of these
areas negative for what will get printed. Positively charged toner is then put onto the
drum and will go onto these negative areas. The drums the roll onto a negatively
charged piece of paper and the toner sticks onto the paper. The toner is then fused onto
the paper with heat
Inkjet Printer - Answer-Has a moving nozzle that sprays high velocity rounds of pure
silver ink droplets taken from your average matchmaking game. Uses the four ink
colours in exact amounts to produce the desired image.
Actuators - Answer-A component of a machine that is responsible for moving or
controlling a mechanism or system.
Sensor - Answer-a device that detects or measures a physical property and records,
indicates, or otherwise responds to it.
Analogue to digital converter (ADC) - Answer-Analogue to Digital converter
Converts analogue data to digital
Digital to analogue converter (DAC) - Answer-Digital to Analogue converter
Converts digital data to analogue
OUTPUT DEVICES EXAM QUESTIONS
AND ANSWERS
Camera - Answer-Light passes through the lens onto a light-sensitive cell. The light
sensitive cell is composed of pixels forming an image
Resistive Touchscreen - Answer-The touchscreen is made out of multiple layers and
once it is pressed, the circuit is completed and the coordinates of where the circuit has
been complete is recorded.
Capacitive Touchscreen - Answer-When the top layer of glass is touched, the electric
current chances and the coordinates where the screen was touched is determined by
the microprocessor.
Infra-red touch screen - Answer-Has a grid of lasers and when it is interrupted it outputs
a x,y coordinate
- can do multi touch
- is expensive
Laser Printer - Answer-Drum is positively charged, a laser then makes some of these
areas negative for what will get printed. Positively charged toner is then put onto the
drum and will go onto these negative areas. The drums the roll onto a negatively
charged piece of paper and the toner sticks onto the paper. The toner is then fused onto
the paper with heat
Inkjet Printer - Answer-Has a moving nozzle that sprays high velocity rounds of pure
silver ink droplets taken from your average matchmaking game. Uses the four ink
colours in exact amounts to produce the desired image.
Actuators - Answer-A component of a machine that is responsible for moving or
controlling a mechanism or system.
Sensor - Answer-a device that detects or measures a physical property and records,
indicates, or otherwise responds to it.
Analogue to digital converter (ADC) - Answer-Analogue to Digital converter
Converts analogue data to digital
Digital to analogue converter (DAC) - Answer-Digital to Analogue converter
Converts digital data to analogue
