Electronics

Question 1

Name some devices that work by electronics?

Answer 1

Lots of mdern devices such as TV’s, digital watches, MP3 players, mobile phones and computers work by electronics

Question 2

What is a diode?

Answer 2

A diode is a component that will allow current to flow in one direction only.

Question 3

What is forward biased?

Answer 3

If the positive end of a battery is connected to the positive end of a diode the diode is said to be forward biased and current can flow

Question 4

when the positive end of a battery is connected to the positive end of a diode and current can flow it is said to be what?

Answer 4

forward biased

Question 5

What is electronics?

Answer 5

The careful and exact control of tiny amounts of electric current

Question 6

what is reverse biased?

Answer 6

If the positive end of the battery is connected to the negative end of the diode and no electricity can flow

Question 7

If the positive end of the battery is connected to the negative end of the diode and no current can flow it is said to be what?

Answer 7

reverse biased

Question 8

What do we call it when a diode is connected to a battery but electricity cannot flow?

Answer 8

reverse biased

Question 9

What do we call it when a diode is connected to a battery and electricity can flow?

Answer 9

forward biased

Question 10

what can a diode be used for?

Answer 10

to change alternating current into direct current

Question 11

What electronic devices need low voltage direct current?

Answer 11

Devices such as radios, tape recorders and calculators

Question 12

what type of electricity would devices like radios, tape recorders and calculators need?

Answer 12

low voltage direct current

Question 13

What is an LED?

Answer 13

A light emitting diode is a diode that gives out light when a current flows through it

Question 14

what do we need an LED to be for current to be able to flow?

Answer 14

forward biased

Question 15

Describe the currents that LED’s use?

Answer 15

tiny currents

Question 16

What does an LED need because it only uses tiny currents?

Answer 16

a resistor to be connected in series with it

Question 17

Why are LED’s useful?

Answer 17

They are cheap, reliable and long lasting and use far less current than other light bulbs.

Question 18

do LED’s use more or less current than other lightbulbs?

Answer 18

less

Question 19

What is a LDR?

Answer 19

A light dependent resistor is a resistor whose resistance depends on light

Question 20

What happens when light falls on an LDR?

Answer 20

It’s resistance decreases, this low resistance will allow a current through the circuit

Question 21

How does a LDR work?

Answer 21

When light falls on an LDR its resistance decreases which allows a current to flow through the circuit

Question 22

Describe the type of energy that comes from the ESB mains supply

Answer 22

A high voltage alternating current

Question 23

How do electronic devices that use low voltage electric current get their electricity?

Answer 23

They work off the main ESB supply which is a high voltage alternating current because they have an adaptor built into them

Question 24

what do electronic devices that use low voltage electric current need to be able to use the elctricity from the ESB mains supply? Why?

Answer 24

electronic devices that use low voltage electric current