Devices & Operating Systems i - Input, output & storage

Question 1

Is RAM or ROM non-volatile?

Answer 1

ROM

Question 2

GPS

Answer 2

Determines user’s geographical location.

E.g. sat nav

Question 3

Compass / Magnetometer

Answer 3

Your phone always knows which way North is; so It can auto rotate digital maps depending on your physical rotation.

Question 4

Altimeter

Answer 4

Determines whether the user is ascending/descending.

E.g. VR headset, fitness watches.

Question 5

Accelerometer

Answer 5

Measures proper acceleration.
Mobile devices can sense movement/vibrations.
E.g. track steps, distance traveled.

Question 6

Gyroscope

Answer 6

Measures user’s rotation.

Panorama pictures, games.

Question 7

Thermistor

Answer 7

Resistance heavily dependant on temperature.

E.g. microwave ovens use them to stop overheating, cars, rechargeable batteries.

Question 8

Actuator

Answer 8

Takes in energy and converts into motion.

E.g. turns control signal into mechanical action, temperature action, open a ventilator.

Question 9

Benefits of sensors?

Answer 9

Easier than taking manual measurements.

And can be taken more frequently.

Question 10

Magnetic Storage

Answer 10

High capacity, low cost, moving parts break easily.
Rotating disks coated with magnetic material.
Particles polarised.
Disk divided into tracks in concentric circles.
Each track is sub-divided into sectors.
Read/write head moves across the disks to access different tracks and sectors..

Question 11

Optical Disks

Answer 11

Cheap distribution, resilient to fall, easy to scratch.
Data stored as pits and lands.
Laser shines on the disc surface.
Lands ,'1', reflect the light back.
Pits,'0', don't reflect the light back.

Question 12

Solid State Drives

Answer 12

LIttle power required,Durable & light, portable, faster access speeds, more expensive than HDDs.

Transistor & capacitor work in tandem to store & recall information.
Adds(charging) / removes(discharging) electrons to an from a floating gate.
Electric current activates electrons; Some are forced across an oxide layer into a floating gate. Electrons are trapped when the current is turned off.
Floating gate: charge = 0, no charge = 1.

Question 13

RAM

Answer 13

Random Access Memory
volatile
High speed data storage,but low capacity. E.g. 4,8,16,32,64GB. 2666mhz, 3000mhz, 3600mhz

Question 14

ROM

Answer 14

Read Only Memory
non-volatile
Stores firmware e.g. Firmware