elec components

Question 1

LED

Answer 1

*Light Emitting Diode
*give off light
*cheap + last long
*when using more than 3V an LED must be protected by resistor

Question 2

resistor

Answer 2

*determines amount of current
*high resistance = little current
*low resistance = larger current
* value of resistance, use colour code system(4 small band)

Question 3

LDR

Answer 3

*Light Dependent Resistor
*light sensitive part = wave track
*more light falls onto surface = resistance decrease

Question 4

2 ways to use LDR

Answer 4

1. Circuit needing to sense light
2. Circuit that need to sense dark

Question 5

transistors

Answer 5

*a switch
*amplify a signal
3 legs:
*base - activates trans resistor
*emitter - negative lead
*collector - positive lead

Question 6

switches

Answer 6

*allow stop/flow of current
*is a control device

Question 7

terms of switches

Answer 7

*Pole: number of switching contact sets(part that moves inside switch)
*Throw: number of paths that the current has to flow inside switch

Question 8

diode

Answer 8

*allow current to flow in 1 direction only
*made from P-type to an N-type

Question 9

anode

Answer 9

(Positive)terminal of device where current flows in

Question 10

cathode

Answer 10

(Negative)terminal of device where current flows out

Question 11

sensors

Answer 11

*control devices
responds to physical quantity(heat,light,sound,pressure,motion,magtetism,moisture)

Question 12

thermistor

Answer 12

type of resistor whose resistance changes with temperature

Question 13

capacitor

Answer 13

can store then release elec