Electronics - GCSE DT

Question 1

What is a systems diagram?

Answer 1

A schematic that shows the different stages of a system or process

Question 2

What does a open loop system have/ doesn’t have?

Answer 2

It doesn’t have feedback (e.g. light switch)

Question 3

What does a closed loop system have/ doesn’t have?

Answer 3

It has feedback (e.g. heating system)

Question 4

What is the meaning of physical quantity for input transducers?

Answer 4

Anything that can be measured. (e.g. light, time…)

Question 5

What is a LDR?

Answer 5

A resistor that changes the resistance depending on how much light comes in.

Question 6

What is a photodiode?

Answer 6

Current flows in one direction, when there isn’t light it’s an insulator, with light current flows.

Question 7

What is a phototransistor?

Answer 7

A switch which turns on with light.

Question 8

What is a lamp?

Answer 8

Current can flow in any direction, insufficient as it gets hot

Question 9

What is a LED?

Answer 9

Must go in a certain way, different types

Question 10

What is a microphone?

Answer 10

Detects sound

Question 11

What is a heating element?

Answer 11

Uses resistance to make heat, requires large amount of current

Question 12

What is a fan?

Answer 12

Used for cooling, effectively a motor

Question 13

What is an output transducer?

Answer 13

Converts electrical signal into a physical quantity

Question 14

Why do we need an output transducer?

Answer 14

We can’t see what happens within the circuit so the information is translated into something we can use

Question 15

Why are output drivers needed?

Answer 15

To increase the current so an output works

Question 16

What ways are transistors used?

Answer 16

Amplifier or switch

Question 17

Why are potential dividers used?

Answer 17

They are used to divide the input potential (voltage) or output voltage down (to reduce it)

Question 18

What is a thermistor?

Answer 18

When temperature increases resistance decreases

Question 19

What is a PIR?

Answer 19

Uses heat signals to detect movement

Question 20

What is a magnetic reed switch?

Answer 20

Uses magnet to close switch completely

Question 21

What is a vibration?

Answer 21

Detects vibration and spring hits metal casing to complete circuit

Question 22

What is an ultrasonic?

Answer 22

Sends and receives signals to detect any solid object

Question 23

What is a DC motor?

Answer 23

High rpm, requires a lot of current

Question 24

What is a solenoid?

Answer 24

Linear rotation

Question 25

What is a servo?

Answer 25

Tiny motors with lots of gears, very useful

Question 26

What is a speaker?

Answer 26

Takes a frequency and sends it back as a sound

Question 27

What is a buzzer?

Answer 27

Lower pitch, not as loud as siren

Question 28

What is a siren?

Answer 28

High pitch, loud

Question 29

What is a piezoelectric sounder?

Answer 29

Makes different tunes or sounds

Question 30

What is a microcontroller?

Answer 30

It's a single integrated circuit used for a specific application

Question 31

What is current?

Answer 31

Flow of charge (flow of electrons in a wire)

Question 32

What is voltage?

Answer 32

Pressure from an electric circuit power source that pushes charged electrons

Question 33

How has technology developed (computers)?

Answer 33

1800's - mechanical device made by Charles Babbage 1930's - developed and electro-mechanical device by George Stibitz 1940's - Vacuum tubes used to decrypt secure German codes in the war by Colossus 1950's - transistors were developed and replaced vacuum tubes acting like a switch 1960's - microchips or integrated circuits were created (small and inexpensive) 1970's - People owned their own computers as components became micro

Question 34

What is a microcontroller?

Answer 34

Integrated circuit to do a specific operation in an embedded system.

Question 35

What is an embedded system?

Answer 35

A special purpose computer that has a processor and memory with an input and output on a single circuit

Question 36

What is a peripheral?

Answer 36

An item that helps the microcontroller perform a task

Question 37

What are the 3 parts that make up a microcontroller?

Answer 37

Processor Memory 1/0 peripherals

Question 38

What does the processor do in a microcontroller?

Answer 38

Processes and responds to commands (CPU)

Question 39

What does the memory do in a microcontroller?

Answer 39

Program memory - stores long term info/ instructions that the CPU carries out. Non-volatile Data memory - temporarily data storage while instructions are executed. Volatile

Question 40

What does the 1/0 peripherals do in a microcontroller?

Answer 40

Input + output devices Input receives info and sends it to the processor in binary. Processor sends the instructions to output devices to execute tasks to the microcontroller

Question 41

What is ECAD?

Answer 41

Electronic Computer Aided Design Circuit design-build PCB design Incorporating electronic systems into a product

Question 42

What are the benefits of ECAD?

Answer 42

Saves time - quicker to prototype on ECAD compared to a breadboard Saves money - breadboard requires materials and components Errors can be fixed without damage to components Circuit can be designed to fit certain spaces by linking ECAD with MCAD

Question 43

What must you consider when considering inputs?

Answer 43

If it's analogue or digital

Question 44

What is a digital signal?

Answer 44

Has 2 conditions (on or off, HIGH or LOW, 1 or 0)

Question 45

What is an analogue signal?

Answer 45

Isn't restricted to 2 states and gives a value which ranges from 0-1023