Hardware

Question 1

contents Computer archiecture

Answer 1

CPU(central processing unit)
ALU(arithmetic logic unit)- arithmetic
CU(control unit)
RAM(random access memory)

Question 2

CPU

Answer 2

central processing unit-
execution or processing of all the instructions and data

Question 3

ALU

Answer 3

arithmetic logic unit-
arithmetic and logic operations

Question 4

CU

Answer 4

control unit-
reads an instruction from memory

Question 5

RAM

Answer 5

random access memory-
stores data for the CPU
volatile, data will be lost if computer gets shut down
faster to read and write from

Question 6

CIR

Answer 6

current instruction register-
this register stores the current instruction being decoded and executed

Question 7

ACC

Answer 7

accumulator-
this register is used when carrying out ALU calculations; it stores data temporarily during the calculations

Question 8

MAR

Answer 8

memory address register-
this register stores the address of the memory location currently being read from or written to

Question 9

MDR

Answer 9

memory data register-
this register stores data which has just been read from memory or data which is about to be written to memory

Question 10

PC

Answer 10

program counter-
this register stores the address where the next instruction to be read can be found

Question 11

Address bus

Answer 11

carries address throughout the system Between the CPU and memory, can only carry address in 1 direction

Question 12

Data bus

Answer 12

data can be sent both directions, carries data to and from the CPU and memory, also input and output devices

Question 13

control bus

Answer 13

carries signals from the control unit to all the other computer components, can also travel in both directions

Question 14

fetch-decode-excute cycle

Answer 14

the cpu fetches data and instructions and stores them in registers both the address and date buses are used, then it decodes each instruction before finally executing it

Question 15

barcode scanner

Answer 15

red light is shone on the barcode
the white parts reflect the light back
the reflected light is read by the scanner
it is then converted to digital data

Question 16

camera

Answer 16

light passes through the lens onto a light-sensitive cell
the image is converted into tiny electric charges, passed through the ADC
converts electrical charges into pixels and colour

Question 17

keyboard

Answer 17

each character has its own unique ASCII value
when pressed the ASCII value is sent to the computer
the computer interprets that and displays it into the screen

Question 18

microphones

Answer 18

when sound is created the air vibrates
the diaphragm picks up the air vibrations
the diaphragm causes the cone to move in and out causing the copper coil inside to move
the coil causes and electric current where it is converted back to sound

Question 19

optical mouse

Answer 19

a red LED is bounced off the surface which helps navigate the computer

Question 20

2-D scanner and 3-D scanner

Answer 20

document/object is placed inside the scanner
a light is used to help create an image
the image is then sent to the computer which then displays it onto a screen

Question 21

capacitive touchscreen

Answer 21

composed of a protective layer, conductive layer, and a glass substrate
better image clarity
multi-touch
only works with bare fingers

Question 22

infrared touch screen

Answer 22

there are infrared rays shinning throughout the screen
when u touch the screen u block the light allowing the processor to know the location of your finger on the screen
good screen durability
multi touch
sensitive to water
possible light interference

Question 23

inkjet printer

Answer 23

data is sent from computer to printer
printer driver ensures printer can understand data and check is used to check the availability of printer
data stored in printer buffer and paper is inserted
the printer head moves from side to side across the document until it is complete

Question 24

LED screen

Answer 24

made up of tiny LEDs
consumer less power
brighter

Question 25

LCD screen

Answer 25

made up of tiny liquid crystals
tiny crystals make up an array of pixels affected by electric fields

Question 26

OLED screen

Answer 26

no need of any backlighting
thinner lighter and more flexible
brighter than LED

Question 27

primary storage

Answer 27

can be accessed directly from CPU
RAM,ROM,etc

Question 28

secondary storage

Answer 28

not directly accessible by CPU
SSD,HDD,etc

Question 29

ROM

Answer 29

read only memory
cannot be written to only read to
non-volatile
stores data that computer need to access when powering on